A photon is an elementary particle that has zero invariant mass and travels in a vacuum with a constant velocity. It is capable of generating electromagnetic phenomena since it carries all forms of electromagnetic radiation:
X-rays Ultraviolet light Visible light Gamma rays Infrared light Radio waves Microwaves and radio wavesThe photon presents wave and corpuscular properties, this means that it behaves as a wave in certain phenomena, such as refraction in a lens; and as a particle when it interacts with matter to transfer energy. The latter is expressed as follows:
[tex]E=\frac{hc}{lambda} = hv[/tex]
E is the energy, in physics it is defined as the capacity to do work.h is Planck's constant, a physical constant that plays a role in the theory of quantum mechanics and it is a constant between the energy of a photon and the frequency of its electromagnetic wave ([tex]E = hv[/tex]) Its value is 6.63 x 10^-34 J/s.c is the speed of light, which is 3x10^8 m/s.lambda (λ) is the wavelength, the distance traveled by a periodic disturbance propagating in one cycle. v is the frequency of the wave, it is the inverse of the wavelength, the number of repetitions per unit time of any periodic event.This means that each photon has energy that is proportional to the frequency of light. In this case, the energy is quantized, which means that the energy of the photons is restricted to certain values. The energy at subatomic levels occurs in packets that refer to the photon, which are the packages of energy and each one correspond to different types of radiation.
This differs from classical waves, which can gain or lose arbitrary amounts of energy.
If we apply the equation and replace the information, we have:
[tex]E=\frac{6.63 x 10^{-34} J/s x 3 x 10^{8} m/s }{498 nm} = 3.99 x 10^{-28} J[/tex]
So 3.99 x 10^-28 J is the amount of energy of the photon of 498 nm emmited from a silicon atom.
Now we will show that the atomic levels are quantized. An atom has ground state (n=1) energy of 13.6 eV. Higher states means the atom is at an excited state. When this happens, an electron from an atom loses energy and makes a transition to a lower state. To avoid this and conserve energy, the atom emits a photon with an amount of energy that equals the difference of energy between a ground state and another state. So we can calculate the energy of the electron in different states.
[tex]E_{n} = \frac{-13.6 ev}{n^{2} }[/tex]
[tex]E_{1} = \frac{-13.6 ev}{1^{2} }=-13.6 ev[/tex]
[tex]E_{2} = \frac{-13.6 ev}{2^{2} }=-3.4 ev[/tex]
[tex]E_{3} = \frac{-13.6 ev}{3^{2} }=-1.511 ev[/tex]
N represents the principal quantum number, which is the overall energy of each orbital. This energy increases as its distance from the nucleus increases. Here we can se that the value of energy of n=1 is higher than energy of n=2, and this one is higher from the energy of n=3. This means each level has a specific energy and it is quantized according to the value of n.
So, a photon is an elementary particle which carries radiation and presents a wave-corpuscle duality, where particles may exhibit wave-like behavior in some experiments while appearing as particles in others. A photon is emmited when an atom loses energy, to conserve this energy and avoid a transition to a lower state. The electron energy is quantized because it is restricted to characteristic values, only taking non-continuous values. In this question, the amount of energy of the photon emmited is 3.99 x 10^-28 J. And the atomic levels are quantized according to the principal quantum number.
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HELP ME THIS IS FOR TODAY!!!!!
Answer:
4. 0.5 kilometers (1st option)
5. 0.1 00 liters (last option)
Explanation:
500 meters to kilometers
4.
1 kilometer = 1000 meters
We use the formula SBD (SMALL TO BIG DIVIDE) i hope this helps you
500 ÷ 1000
= 0.5 kilometers
5.
100 milliliter to liter
SBD
100 ÷ 1000
= 0.1 00 liters
What makes an atom radioactive?
Answer:
The unstable nucleus of radioactive atoms emit radiation.
Explanation:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced and unstable, or radioactive.
(https://www.epa.gov/radtown/radtown-radioactive-atom-activity-4-atomic-stability)
Answer:
When the atoms of an element have extra neutrons or protons it creates extra energy in the nucleus and causes the atom to become unbalanced or unstable. Whether radioactive elements can become stable and if so, how. The unstable nucleus of radioactive atoms emit radiation. ... This process is called radioactive decay.
Explanation:
what is the molecular weight of H2so4?
Lets find
[tex]\\ \sf\longmapsto H_2SO_4[/tex]
[tex]\\ \sf\longmapsto 2(1u)+32u+4(16u)[/tex]
[tex]\\ \sf\longmapsto 2u+32u+64u[/tex]
[tex]\\ \sf\longmapsto 34u+64u[/tex]
[tex]\\ \sf\longmapsto 98u[/tex]
what evidence have you discovered to explain how the fossil record provides relative ages? use the words: mass extinction, superposition, fossils, and relative age
Answer:
Relative dating is based on the positions of fossils in rock layers. Lower layers were laid down earlier, so they are assumed to contain older fossils. This gives the fossil an approximate age in years. Absolute dating is often based on the amount of carbon-14 or other radioactive element that remains in a fossil up until extinction.
Relative dating is a method of dating where the geologic events are arranged and the rocks are left behind in a sequence. They function on the basis of the stratigraphy and don't provide us with actual numeric data.
It provides us with the relative ages such as mass extinction the fossils are superimposed. It is based on the position of fossils in the layers of the rocks.Learn more about the discoveries to explain how the fossil record.
brainly.com/question/22311467.
A brick has a mass of 100 G and a volume of 25CM3 what is the density of the brick
Answer:
[tex]\boxed {\boxed {\sf 4 \ g/cm^3}}[/tex]
Explanation:
We are asked to find the density of a brick. Density is a substance's mass per unit volume. The formula for calculating density is as follows.
[tex]\rho= \frac{m}{v}[/tex]
The mass of the brick is 100 grams and the volume is 25 cubic centimeters.
m= 100 g v= 25 cm³Substitute the values into the formula.
[tex]\rho= \frac{ 100 \ g}{25 \ cm^3}[/tex]
Divide.
[tex]\rho=4 \ g/cm^3[/tex]
The density of the brick is 4 grams per cubic centimeter.
i will mark brainliest if you are correct
Which statement about pure substances and elements is correct?
a
All pure substances are elements.
b
All elements are pure substances.
c
Pure substances cannot be elements.
d
Elements cannot be pure substances.
The statement about pure substances and elements correct is all elements are pure substances ,therefore option (b) is correct .
What do you mean by the elements ?An element is a pure substance whose atoms all have the same number of protons.
Elements are the simplest chemical elements and thus can not be broken down through chemical reactions.
Characteristics of element -:
Elements cannot be broken down into simpler substances by the chemical reactions. Each element is represented by a unique symbol.The atomic number gives a distinct identity to a chemical element.The statement about pure substances and elements correct is all elements are pure substances ,therefore option (b) is correct .
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Calculate the empirical formula of a compound that has a composition of 5.9% (by mass) hydrogen and 94.1% (by mass) oxygen.
Answer:
[tex]oxygen \: at \: 94.1\% \: hydrogen \: at \: 5.9\% \\ at \: 100gram \: oxygen \: \\ \: 94.1\% = .941 \times 100g \\ = 94.1 \times \frac{1mol}{16g} = 5.88g \\ hydrogen \: \\ 5.9\% = .059 \times 100 = 5.9 \times \frac{1mol}{1.002g} = 5.88g \\ here \: oxygen = hydrogen \: so \: ratio \\ = 1 \: \: \: 1 \: \\ emperical \: formula \: = oh\\ thank \: you[/tex]
Composition:
5.9% Hydrogen and 94.1% Oxygen (by mass)
in a 100 gram sample:
5.9 gram Hydrogen
94.1 gram Oxygen
Finding the number of moles:
Moles of Hydrogen:
moles = given mass/ molar mass
moles = 5.9 / 1 [molar mass of Hydrogen = 1g/mol]
moles of hydrogen = 5.9 moles
Moles of Oxygen:
number of moles = given mass / molar mass
number of moles = 94.1 / 16 [molar mass of Oxygen = 16g/mol]
moles of Oxygen = 5.88 ≈ 5.9 moles
Empirical Formula:
Moles of Hydrogen : Moles of Oxygen
5.9 : 5.9
Moles of Hydrogen : Moles of Oxygen = 1:1
Empirical Formula = OH
Polar molecules have partial positive and partial negative charges. An electrical
attraction between the partial positive charge of one polar molecule and the partial
negative charge of another polar molecule is called a/an
Answer:
Image result for Polar molecules have partial positive and partial negative charges. An electrical attraction between the partial positive charge of one polar molecule and the partial negative charge of another polar molecule is called a/an
A polar molecule has a net dipole as a result of the opposing charges (i.e. having partial positive and partial negative charges) from polar bonds arranged asymmetrically. Water (H2O) is an example of a polar molecule since it has a slight positive charge on one side and a slight negative charge on the other.
Explanation:
What is your experience in stars??
Answer:
Experience in star is very nice
Explanation:
Because i love stars
What correctly describes the melting of a solid
The particles in the solid LOSE enough energy to OVERCOME the interactions between the particles
The particles in the solid GAIN enough energy to FORM the interactions between the particles
The particles in the solid GAIN enough energy to OVERCOME the interactions between the particles
The particles in the solid LOSE enough energy to raise the temperature of the solid enough to turn it into a
liquid
Answer:
A reaction in which heat is absorbed by reactant molecules and energy of products become more than reactants is known as an endothermic reaction
how does calcium atomic radius compare to magnesium (Mg) radius and patssiuks (K) redius?
Answer:
The radius of a calcium atom would be larger than that of a magnesium atom.
The radius of a calcium atom would be slightly smaller than that of a potassium atom.
Explanation:
Refer to a modern copy of the periodic table.
Calcium and magnesium are in the same column. They are in the same group (IUPAC group [tex]2[/tex].)
Hence, atoms of calcium and magnesium would have similar effective nuclear charges. In other words, the attraction between a calcium atom nucleus and its valence electrons would be similar to that of magnesium.
However, calcium is in the fourth row of the periodic table (fourth period) while magnesium is in the third (third period.) A calcium atom would thus have four main shells with electrons. In contrast, a magnesium atom would only have three such main shells.
Despite the similar effective nuclear charge (effective attraction on the outermost electrons,) the radius of a calcium atom would be larger than that of a magnesium atom because of the extra main electron shell.
On the other hand, calcium and potassium are in the same row (same period.) A calcium atom and a potassium atom would both include four electron-filled main shells.
However, with one additional proton per atom, the effective nuclear charge of calcium atoms would be greater than that of potassium atoms. Hence, when compared to potassium nuclei, the nucleus of a calcium atom would pull its electron shells closer to the center. The radius of a calcium atom would thus be smaller than that of a potassium atom.
In general, atomic radius would generally become larger when moving down a column in the periodic table. On the other hand, atomic radius would general become smaller when moving towards the right-hand side of a row in the periodic table.
What distinguishes a chemical property from a physical property?
A. Chemical properties describe the characteristics of a substance that are directly observable without changing the substance.
B. Chemical properties are only observable when a substance changes into a new substance.
C. Chemical properties always change depending on temperature or pressure.
D. Chemical properties only describe subjective characteristics that cannot be measured with scientific tools.
C. Chemical properties always change depending on temperature or pressure.
Physical Change v/s Chemical Change:
Physical changes are reversible in nature while chemical change leads to the formation of new products.No new substance is formed in a physical change while it occurs in case of chemical change.A physical property is a characteristic of a substance that can be observed or measured without changing the identity of the substance while a chemical property describes the ability of a substance to undergo a specific chemical change.When the reactants are mixed, the temperature change caused by the reaction is an indicator of a chemical change. Thus we can say that chemical properties always change depending on temperature or pressure.Learn more:
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This scale is being used to measure flour. What is the
scale really measuring about
the flour?
A. the color of the flour
B. the volume of the flour
C. the weight of the flour
D. the temperature of the
flour
Someone plz help me !!
Science
Or
Bias?
How could you describe the changes that happen when carbon changes form from graphite to diamond
-it is a chemical change, but the intensive and extensive properties of carbon will be maintained
-it is a physical change, but the intensive and extensive properties of carbon will be maintained
-it is a chemical change, which could change some of the intensive and extensive properties of the carbon
-it is a physical change, which could change some of the intensive and extensive properties of the carbon
The correct answer is: it is a chemical change, which could change some of the intensive and extensive properties of the carbon.
To answer this question, we must bear in mind that a chemical change involves the breaking of bonds in a substance and subsequent rearrangement of atoms to form a new substance.
This is why we say that in a chemical change, new substances are formed. Another name for a chemical change is a chemical reaction.
Having said that, it is clear that as graphite changes to diamond, bonds are broken and carbon atoms are rearranged.
This rearrangement of atoms leads to different intensive and extensive properties for graphite and diamond. For instance, graphite conducts electricity but diamond does not conduct electricity. Also, diamond is much denser and harder than graphite. A physical change can not lead to change in some of the intensive and extensive properties of the carbon.
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What series does the following compound belong to?
Answer:
B
Carboxylic acid
Explanation:
I'm not entirely sure, but this should be it
Can I please have help on a Timer
Answer:
cell
tissue
organ
organ system
Explanation:
the cell is the smallest
a tissue looks like a unit
an organ is multiple units
organ systems are the full body
A factor is an experiment that can change is a(n)
Answer:
Option 2 variable
Explanation:
Answer:
variable.
Explanation:
A variable is anything that can change or be changed. In other words, it is any factor that can be manipulated, controlled for, or measured in an experiment.
How does the amount of oxygen in the water affect the oyster population constant/variables and what is the hypothesis/predication
Answer:
Lack of oxygen can cripple the oysters' ability to fight off the parasite Perkinsus marinus that causes Dermo and slowly takes over their bodies.
Which element would most likely lose electrons to form positive ions when bonding with other elements?
rubidium (Rb)
gallium (Ga)
argon (Ar)
iodine (I)
The correct answer to the question is Rubidium (Rb)
Rubidium (Rb) is a group 1 element and as such, it can form bond by losing it's valence electron (i.e 1 electron) easily.
Gallium (Ga) is a group 13 element. It can only form bond by losing it's 3 valence electrons.
Argon is a group 18 element. This group has completely filled outermost shell and are very stable. They do not involve in bond formation.
Iodine (I) is a group 17 element. It is more difficult for this group to lose its 7 valence electrons hence, they form bond by accepting 1 electron.
With the above information, we can conclude that Rubidium will most likely lose electron to form bond.
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Answer:
(Question 1)Which element would most likely lose electrons to form positive ions when bonding with other elements?
(Answer) rubidium (Rb)
(Question 2) Which statement about sodium chloride is correct?
(Answer) The sodium atom transfers electrons to the chlorine atoms to form ionic bonds.
(Question 3) Based on their locations in the periodic table, which two elements are most likely to form covalent bonds with each other?
(Answer) nitrogen (N) and oxygen (O)
(Question 4) Which phrase best describes electronegativity?
(Answer) the relative strength with which an element attracts electrons in a chemical bond
(Question 5) Based on the information in the table, which pair of elements would likely form the least polar bonds with each other?
(Answer) bromine and nitrogen
Explanation:
just finished the quick check enjoy UwU
3
A substance dissolves in water to form a colourless solution. This solution reacts with aqueous
silver nitrate in the presence of dilute nitric acid to give a yellow precipitate.
What is the possible identity of the substance?
A А
calcium iodide
B
copper(II) chloride
Ciron(II) iodide
D
sodium chloride
Answer:
D) sodium chloride
i think this is the answer
Explanation:
Help me with this easy chemical change question!!!!
Answer:
1, just I) color.
Physical properties are the properties that can be observed without changing the composition of a substance, such as color, temperature, density, and boiling point.
A physical change is a change in the substance that only modifies its aggregation state, such as solidification, and boiling.
Chemical properties are the properties that need a reaction to being observed, such as combustibility, which needs a combustion reaction to being quantified.
When a chemical reaction occurs, and the composition of the substance change, it's a chemical change.
So, heating copper with carbon is a chemical reaction, and purification by electrolysis is too. Color is the only physical property.
descoberto em 1996 por pesquisadores alemães o novo elemento químico de numero 112 poderá ser batizado de copernicium em homenagem ao cientista e astronomo Nicolau Copérnico segundo os cientistas o elemento é aproximadamente é 277 vezes mais pesado que o hidrogênio, o que torna o elemento mais pesado da tabela periódica ocupando a posição relativaa ao 7°periodo do grupo 12. A tabela periódica, uma das realizaações mais notáveis da quimica, foi desenvolivda exclusivamente a partir das propriedades fisícas e químmicas dos elementos e, por isso, o conhecimento da posição ocupada por um elemento químico permite que se façam algumas previsões quanto às suas propriedades.
considerando a localização dos átomos dos elementos químicos x, y e z na tabela periódica é incorreto afirmar que
x = 3° período do grupo 1 (I A)
y = 2° período do Grupo 14 (IV A)
z = 2° período do grupo 16 (VI A)
Answer:
Loading...
Explanation:
difference between atom and ion
plz plz answer
Answer:
Atoms are neutral; they contain the same
samenumber of protons as electrons. By
definition, an ion is an electrically charged
particle produced by either removing
produced by either removingelectrons from a neutral atom to give a
produced by either removingelectrons from a neutral atom to give apositive ion or adding electrons to a neutral atom to give a negative ion.
Please help!
Best answer with explanation will be marked brainliest.
Explanation:
I think it is d because it is a gas
Magnesium occurs naturally in only three isotopes. ^24 Mg has an isotopic mass of 23.9850 amu and an abundance of 78.99%. ^25 Mg has an isotopic mass of 24.9858 amu and an abundance of 10.00%. Find the mass number of the last isotope of magnesium.
Can someone please explain how to solve this? *done mine the notes*
Answer:
25,98 amu and 11.01% abundance
Explanation:
1. Find the missing abundance
100 - 78.99 - 10 = 11.01 %
2. Using each mass and abundance and the periodic table for the Mg amu
And let Isotope = Mg
23.9850(78.99%) + 24.9858(10%) + Mg(11.01%) = 24.305 (100%)
Solve for Mg
Mg = 25,98
The equation shows the reaction of sulfuric acid with sodium hydroxide:
H2SO4 + 2NaOH --> NaSO4 + 2H2O
25 cm^3 of sulfuric acid of concentration 0.2 mol/dm^3 reacted with exactly 10 cm^3 of sodium hydroxide. Calculate:
a) the number of moles of sulfuric acid present
b) the number of moles of sodium hydroxide reacting
c) the concentration of the sodium hydroxide in mol/dm^3
Answer:
(a).
[tex]{ \sf{1000 \: {cm}^{3} \: contains \: 0.2 \: moles \: of \: acid}} \\ { \sf{25 \: {cm}^{3} \: contains \: ( \frac{25 \times 0.2}{1000} ) \: moles}} \\ \\ = { \sf{0.005 \: moles}}[/tex]
» 0.005 moles of sulphuric acid are present.
(b).
from the equation:
[ 1 mole of acid reacts with 2 moles of sodium hydroxide ]
[tex]{ \sf{1 \: mole \: of \: acid \: reacts \: with \: 2 \: moles \: of \: hydroxide}} \\ { \sf{0.005 \: moles \: of \: acid \: react \: with \: (0.005 \times 2) \: moles}} \\ { \sf{ = 0.01 \: moles}}[/tex]
» 0.01 moles of sodium hydroxide reacted.
(c).
[tex]{ \sf{10 \: {cm}^{3} \: contains \: 0.01 \: moles \: of \: hydroxide }} \\ { \sf{1000 \: {cm}^{ 3} \: contain \: ( \frac{1000 \times 0.01}{10} ) \: moles}} \\ \\ { \sf{ = 1 \: mol \: {l}^{ - 1} }}[/tex]
» concentration is 1 M
For the following pairs of ions, use the concept that a chemical compound must have a net charge of zero to predict the formula of the simplest compound that the ions are most likely to form. Write the formula of the metal first and follow by the non metal
[tex]\\ \sf\longmapsto FeP[/tex]
[tex]\\ \sf\longmapsto Fe_2S_3[/tex]
[tex]\\ \sf\longmapsto FeCl_2[/tex]
[tex]\\ \sf\longmapsto MgCl_2[/tex]
[tex]\\ \sf\longmapsto MgO[/tex]
[tex]\\ \sf\longmapsto Mg_3N_2[/tex]
[tex]\\ \sf\longmapsto Na_3P[/tex]
[tex]\\ \sf\longmapsto Na_2S[/tex]
[tex]\\ \sf\longmapsto CoO[/tex]
[tex]\\ \sf\longmapsto Co_2S_3[/tex]
[tex]\\ \sf\longmapsto AlCl_3[/tex]
[tex]\\ \sf\longmapsto CsBr[/tex]
[tex]\\ \sf\longmapsto Ti_2O_4[/tex]
[tex]\\ \sf\longmapsto Ag_2S[/tex]
1. A (blank) determines what will be tested in a scientific experiment.
Answer:
Hypothesis
Explanation:A hypothesis is what gives the user the directions of the lab and what needs to be done for the procedure
A student is working hard on a chemistry lab experiment that uses a strong acid. Halfway through the lab, the student gets hungry and starts eating a bag of chips. When the student licks their fingers, they start to have a severe reaction. summary