1. Lanthanides and actinides are kept separately in the modern periodic table. Why?
2. Differentiate between long period and short period in any two points.
- Help!! Random / Plagiarised answers will be reported! *
Answer:
1.. Lanthanides and actinides are kept separately in the modern periodic table Why?
Lanthanides and actinides are kept separately in the modern periodic table because of following reason:
If they are placed in the body of the periodic table, the periodic table will become extremely long and hard to recognizemore scientific and technical reason why they chose to keep the lanthanides and actinides away from the rest of the periodic table was to help in the grouping of elements in blocksExplanation:
2. Differentiate between long period and short period in any two points.
Long period:
The 4th and 5th periods of the periodic table are called long periods. The long periods coontain 18 elements in themshort period:
The 2nd and 3rd periods of the periodic table are called short periods. The short periods contain 8 elements in themHow many moles of water are in 1.23x10^18 water molecules?
in scientific notation
Answer:
1.23x10^24 atoms/6.022x10^23 atom/mol = 2.04 mol H20
Explanation:
What is an element?
A. A substance made up of all the same type of atoms
B. A substance made up of different kinds of atoms
Answer:
A
Explanation:
element is a pure substance consisting only of atoms
GIVING 20 POINTS!! Apply Concepts Two chemists each plan an investigation in which they will combine hydrogen gas with chlorine gas to observe the chemical reactivity. The plans differ in that one will use 25 milligrams each of hydrogen and chlorine, and the other will use 1000 times this amount, i.e., 25 grams each of hydrogen and chlorine. Can the investigations reach similar conclusions about the reactivity of hydrogen with chlorine? Explain.
Answer:
Yes, the investigations will reach similar conclusions about the reactivity of H2 and Cl2
Explanation:
1. The law of multiple proportions says that when elements form compounds, the proportions of the elements in those chemical compounds can be expressed in small whole number ratios. This means that regardless of whether 1000 times more of the products are used, the reactivity of the products is established by the chemical reaction
2. The law of multiple proportions is an extension of the law of definite composition, which states that compounds will consist of defined ratios of elements.
3. A reaction with more reactants will need more care because more products are produced, which can be toxic
4. H2 and Cl2 reactivity does not depend on the quantities but the chemical properties of each compound
When scientists talk about mass and volume, they are talking about which
of these?
A. energy
B. heat
C. matter
D. a vacuum
Answer:
C. Matter
Explanation:
Answer:
C. Matter
Explanation:
Matter is anything that occupies space(volume) and has mass.
What is the name of this ??
Answer:
Explanation:
Your answer is C
A compound contains only carbon, hydrogen, and oxygen. Combustion of 8.544 mg of the compound yields 12.81 mg CO2 and 3.50 mg H2O. The molar mass of the compound is 176.1 g/mol. What are the empirical and molecular formulas of the compound
Answer:
The empirical formula is the formula with a minimum whole number ratio of the constituent atoms present in a molecule. While the molecular formula has the actual number of atoms of various elements present in the molecule of the substance.
Empirical formula is C₃H₄O₃
Molecular formula is C₆H₈O₆
This question involves finding the empirical and molecular formulas. Empirical formula is the one where minimum whole number ratio of the constituent atoms present in a molecule is shown whereas molecular formula is the one that shows the number of each type of atom that are present in a molecule.The compound contains only carbon, oxygen and hydrogen and undergoes combustion. Thus;[tex]C_{x}[/tex][tex]H_{y} O_{z}[/tex] + O₂ ⟶ xCO₂ + [tex]\frac{y}{z} H_{2} O[/tex]
The combustion yields 12.81 mg of CO₂.From online sources, molar mass of CO₂ = 44 g/mol
number of moles of CO₂ = 12.81/44 = 0.291m mol
Mass of carbon in it is; C = 12 × 0.291 = 3.492 mg
Similarly the combustion yields 3.50 mg H2O.molar mass of water = 18 g/mol
number of moles of water in it = 3.5/18 = 0.194m mol
Hydrogen has 2 nos in water and so;
number of moles of hydrogen = 2 × 0.194 = 0.388m mol
Mass of hydrogen = 1 × 0.388 = 0.388 mg
Compound is 8.544 mg and so;Oxygen mass = 8.544 - (3.492 + 0.388) = 4.664 mg
Similarly, moles of oxygen that has molar mass of 16 is;
no of moles of oxygen = 4.664/16 = 0.2915m mol
Thus;Ratio of C:H:O is; 0.291:0.388;0.2915
Simplifying this gives us the empirical formula ratio as;
3:4:3
Thus;
Empirical formula is C₃H₄O₃
Molar mass of C₃H₄O₃ = (12 × 3) + (1 × 4) + (16 × 3) = 88 g/molWe are told that the molar mass of the compound is 176.1 g/mol.
Thus;
Molecular formula is; (176.1/88)C₃H₄O₃ = C₆H₈O₆
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Explain how heat is conducted along a metal bar.
It causes the particles to vibrate and this causes the neighbouring particles to vibrate.
this process is continued until particles at the other vibrates.hence heat is transmitted from one place to another .Also it causes electrons to collide with the atoms of the metal.
Water from this pot is changing from a liquid to a steam. Which process is taking place?
A. condensation
B. Boiling
Answer:
Boiling B.
Explanation:
Mi One should know the properties of the components of the mixture to separate it. Explain with an example.
Someone plz help me :(
Answer:
B and A.
Explanation:
Many of the great scientists were religious. But the answer is not D.
A scientist may have strong opinions. That was certainly true of Newton. Most of the time he was right. Still the answer is not C. Science requires an open mind.
The answer is between A and B. Many discoveries were made looking at the natural world. That may provide the inspiration. But I don't think it is the answer. I'm going to say A
B is the other answer. Between A and B many scientific truths have been discovered.
In the following image, atoms are represented by colored circles. Different colors represent different types of atoms. If atoms are touching,
they are bonded.
Which of the following boxes shows only one type of element?
A. B
B. A
C. C
D. E
Answer: C
Explanation: Only one color (element) appears in C. The other options have at least 2 colors.
How many nickels are there in $5.25?
Answer:
105
Explanation:
1 nickel = 5 cents
5.25 dollars x 100 cents
= 525 cents
525 cents / 5 cents
= 105 nickels
PLEASE HELP ASAP !!! WILL GIVE BRAINLIEST
What were the changes to the atomic model over time?
Answer:
The atomic model started out as a large single ball, then with electrons attached to it. It then became "planetary model" with electrons orbiting at specific levels, and then later one with a nucleus or multiple different particles like protons and neutrons, and electrons orbiting at general (but not specifically predictable) areas.
Explanation:
thank u :)
[tex]\huge\mathfrak\red{❥︎QuEsTioN}[/tex]
What is the Molecular mass of Feso4(NH4)2so4.6h2o
[tex]\\ \sf\longmapsto FeSO_4(NH_4)_2SO_4.6H_2O[/tex]
[tex]\\ \sf\longmapsto 56u+32u+4(16u)+2(14u+4\times 1u)+32u+4(16u)+2(1u)+2(16u)[/tex]
[tex]\\ \sf\longmapsto 120u+64u+56u+64u+2u+32u[/tex]
[tex]\\ \sf\longmapsto 120u+120u+98u[/tex]
[tex]\\ \sf\longmapsto 240u+98u[/tex]
[tex]\\ \sf\longmapsto 342u[/tex]
Answer:
[tex]\huge\mathfrak\green{hola}[/tex]
How is bacteria are different from animals?
Answer:
Bacteria has 1 cell and An Animal has multiple cells.
Explanation:
Bacteria is a cell its self. While An Animal, It has multiple cells that create multiple tissues, and those tissues create multiple organs, those organs make up an organ system. After the Organ System, it's an organism.
Organism = Animal, Human, Ect.
Meanwhile, Bacteria is made up ONE CELL (bacteria it's self is 1 cell)
So the answer is "Bacteria has 1 cell and An Animal has multiple cells."
I hope this helped!! <33
Plzzzzzz help me Write electronic configuratof sodium and chlorine in the term of subshell ?
Answer:
ans:Ne=2,8,1
ans:2,8,7
Which list includes terms that only describe carbon dioxide, (CO2)?
a
molecule, compound, mixture
b
molecule, compound, pure substance
c
atom, element, mixture
d
atom, element, pure substance
Answer:
b. molecule, compound, pure substance
Terms that only describe carbon dioxide are molecule, compound, pure substance.
What is mixture and compound?In chemistry mixture is a combination of two or more different chemical elements which are not chemically bond. A mixture is the physical composition of two or more elements in which their individual identities are vanished and it also mixed by solutions, suspension and colloids.A compound can't be separate by physical separation and after the mixture you can't identified that it is compound or not.
In chemistry compound is combination of two or more different elements which are chemically bond. So compound is made up of chemical bond. A compound can't be separate by physical separation and after the mixture you can't identified that it is compound or not.A mixture is the physical combination of two or more elements in which their individual identities are retained and it also mixed by solutions, suspension and colloids.
Therefore, terms that only describe carbon dioxide are molecule, compound, pure substance.
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What are the missing coefficients for the chemical equation
[ ] C2H2 + [ ] O2 → [ ] CO2 + [ ] H2O
Answer:
2C2H2 + 5O2 → 4CO2 + 2H2O
Explanation:
If aluminium has an atomic number of 13and has 14 neutrons what is its mass number
Answer:
27
Explanation:
mass number A = atomic number z + number of neutrons = 13+14= 27
Answer:
Explanation:
27
Difference between pulley and wheel and axle..
Explanation:
Difference between pulley and wheel and axle are:
pully = A pulley is a circular disc that has a groove around the circumference over which a rope or string can move. In the pulley, load is connected to one end of the rope and effort is applied on the other ends . The pulley that does not move up and down is called the fixed pulley.
Wheel and axle= Wheel and axle consists of two cylinders of different radii. The cylinder of large radius is called wheel and the cylinder radius is called axle . Both wheel and axle move together under the application of effort.
I have send you a photo of wheel and axle, pulley.
I hope it will help you so.
5
Which of the following is true regarding the particle nature of a solid?
Particles in a solid -
A
move very little, so it cannot easily change its shape.
B
are relatively far apart, so it is highly compressible.
с
are in continual motion, and can slide past each other.
D
are very far apart, so it can easily change its shape.
Answer:
this answer is b no u can it very easy
Explanation:
because solid and liquid can compress easily
plz support me
Answer:
A. move very little, so it cannot easily change its shape.
What are the characteristics of a scientist?
Answer:
some of the main characteristics of a scientist are:
1. careful observation
2. curiosity
3. creativity
4. skepticism
5. objectivity
Explanation:
hope that helps>3
3
Explanation:
hopes it help you good luck
Which two elements have the same number of energy levels with electrons in them?(1 point)
A_ krypton and neon
B_ boron and oxygen
C_ lithium and francium
D_ neon and sodium
Its B) Boron and Oxygen
The correct answer is B.
boron and oxygen have the same number of energy levels with electrons in them.
The energy level of an element is the region around the nucleus where its electron is likely to be, this corresponds to the period of the element in the periodic table.
Elements found in period 1, have one energy level.
Elements found in period 2, have two energy level.
Examples of elements found in period 2 include:
lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neonIn the given options, only option B contains two elements with 2 energy level.
Thus, boron and oxygen have the same number of energy levels with electrons in them.
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How does the density of one marble compare with the density of six of the
marbles?
Answer:
Since, density is mass per unit volume, the density is the same.
The density of the marbles will depend upon their mass and volume, not on their count.
What is the density?The density of an object is measured as the mass per unit volume. The average density equals the total mass of the object divided by its total volume.
The formula of the density of the material is expressed as follows:
Density = Mass/Volume
The S.I. unit of the density is Kg/m³. The density of a material is an intrinsic property as it doesn't depend on the size. If the size of the object increases, the mass increases as well but the density of material remains constant.
If the density of each marble is the same then the density of six marbles will be the same as the one marble because the density of marble is an intrinsic property. The density of marbles does not depend upon the number of marbles.
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Which of the following statements about alcohols is false?
A. Ethanol is soluble in water.
B. Ethanol has a higher boiling point than ethane.
C. Ethanol produces hydrogen when it burns.
D. None of these
Answer:
It's C. Ethanol produces hydrogen when it burns
When burned, ethanol produces water and CO2.
what is the mass of 0.2 moles of ethanol
Answer:
Answer is 9.2 grams
Explanation:
Molar mass of ethanol
[tex]{ \bf{CH _{3}CH_{2}OH}} = (12 \times 2) + (6 \times 1) + (16) \\ = 46 \: g[/tex]
for moles:
[tex]{ \sf{1 \: mole \: of \: ethanol \: weighs \: 46 \: g}} \\ { \sf{0.2 \: moles \: weigh \: (0.2 \times 46) \: g}} \\ = 9.2 \: g[/tex]
If an object is travelling 25.0 meters/second, how long will it take to travel 1.5 km?
Answer:
60 sec
Explanation:
in 1.5km there is 60 unit of 25 meter so
If I have 4.9 moles of gas at a pressure of 2.0 atm and a temperature of 56 Celsius, what is the volume of the cantainer that the gas is
in? (R=0.0821 L*atm/mol*K)
Answer: 132 liters. or 130 liters with 2 sig figs.
Explanation: Use the ideal gas law: PV = nRT
We want V, so rewrite and plug in data:
Temperture must be in Kelvin (add 273.15 to
V = (nRT)/P
V = (4.9 moles)*(0.0821 L*atm/molK)*(328.2K)/(1atm)
V = 132 liters (3 sig figs). 130 liters with 2 sig figs
How does an atom change if all of its electrons are removed?
How does an atom change if all of its electrons are removed?
The atom’s volume increases.
The atom’s mass increases.
The atom becomes positively charged.
The atom becomes negatively charged.
Answer:
c
Explanation:
it becomes positively charged
Answer:
The atom becomes positively charged.
Explanation:
If ALL OF THE ELECTRONS are removed, then there are, no matter what, less electrons than protons in an atom. And, since the atom has less electrons than protons, it becomes positively charged.