Answer:
chromatography is based on the principle where molecules in mixture applied onto the surface or into the solid, and fluid stationary phase is separation from each other while moving with the aid of a mobile phase.
Can you join please.
It's urgent for help.
(Physical Science)
Which group of metals includes elements with one valence electron? (1 point)
A. alkaline earth metals
B. rare earth metals
C. alkali metals
D. transition metals
Answer:
C
Explanation:
alkali metals are the Group I elements, which have 1 electron in their valence shells
Answer:
Alkali metals are the elements which have only one valence electron in their outermost or ultimate shell.
Explanation:
Alkaline Earth metals have 2 valence electron in their outermost shell and readily give up their 2 electron to achieve stability.
Rare Earth Metals have 3 valence electron in their outermost shell and they have high magnetic moments and divert range of magnetic structure.
Alkali Earth metals have 1 valence electron.
Transition metals generally have 2 valence electron .
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Which of the following statements correctly explains why the excretory system is different from the digestive system? (1 point)
The excretory system is different from the digestive system because it removes waste from the body by filtering water, which
includes mostly the by-products of metabolism.
The excretory system is different from the digestive system because it removes waste from the body by filtering urine, which
includes mostly the by-products of metabolism
The excretory system is different from the digestive system because it removes waste from the body by filtering food, which
includes mostly the by-products of metabolism. filtering food
SS
2
The excretory system is different from the digestive system because it removes waste from the body by filtering blood, which
o
includes mostly the by-products of metabolism
U.
Hey
Answer:
The excretory system removes waste from the body. remove waste from the blood. The digestive system breaks down the food you eat into nutrients that provide energy and building materials for cells. The digestive and excretory sytems work together to process the food that you eat.
How could you describe the changes that happen when carbon changes form from graphite to diamond?
The change from graphite to diamond is a chemical change.
A chemical change involves the rearrangement of atoms in a substance. In other words, the "composition" of the substance changes when a chemical change takes place.
This is clearly seen when graphite changes to diamond. The arrangement of carbon atoms changes as reflected by the change in the density of graphite when it is converted to diamond.
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place the letters on the spectrum below from least scientific two more scientific A. All living things are composed of one or more cells. We know this because every living thing examined to date has
been found to be composed of one or more cells.
B. If you break a mirror, you will have seven years of bad luck.
C. The Earth is flat. Anybody can see that!
D. Taking Vitamin C prevents the common cold. Linus Pauling, the Nobel laureate who discovered the structure of
Vitamin C, says it does.
E. Humans have a soul. I believe this because it says so in the Bible. The soul is what separates us from animals.
F. The rate of acceleration of all falling objects on Earth is constant. Two spheres of identical diameter and volume are
dropped from the top of a building; one is made of steel, the other made of a plastic polymer. They both will accel-
crate at the same rate (32 ft/s) and hit the ground at the same time.
Answer: B, C, E, D, A, F
Explanation: It is a little difficult to assign a regid order to these statements. Much depends on one's definition of "more scientific." My thoughts:
B: Only in the movies
C: Flat Earthers still exist, but no one has ever fallen off the edge, that I'm aware of
E: I've had a few pets with souls. My cat has it in for me.
D: I met Linus Pauling twice - he was too enthusiastic with his vitamin C and did not critically evaluate the evidence, but he was far more correct than the Flat-Earthers.
A: Lots of good evidence, although it can also depend on the definition of "living," Is a virus "living?"
F: Yep, I've done it myself. Heavier object have more inertia - they are the couch potatoes of physics. They will take their own time to get moving.
A car start from rest and covers distance of 100m after 10seconds.if the acceleration is 2m/s square, calculate the final velocity..
Answer:
20 m/s
Explanation:
solution,
initial velocity (u)=0 m/s
Distance covered(s)=100m
Time taken(t)=10 seconds
Acceleration (a)=2m/s²
Now,
By using first equation of motion, we have
v=u+at
=0+2×10
=20 m/s
I hope it helped U
stay safe stay happy
Which of the following best describes a scientific model?
Question 6 options:
Something used to represent an idea or process
A way to prove a theory is true
A direct experience in nature
A prediction that can be tested
Explanation:
idea= hypothesis
xperience in nature= read Darwin's theory..
with birds from Galapagos island or rain forest environment., had proven that the shape of a bird's beaks, determined what their diet consisted of In the wild.
captured birds from such countries, has proven, an omnivore or seed eater...through testing plus dissection.
heleep I don't understand
Answer:
Loading...
Explanation:
Answer:
This is animal shell
Explanation:
Because it shape and size is in circular shape of body so we can find the types
When measuring the volume of an object you are finding the?
A. Single dimension of an object
B. Amount of 2 dimensional space an object covers
C. Amount of 3 dimensional space the object occupies
D. Amount of 4 dimensional space an object occupies
Answer:
C. Amount of 3 dimensional space the object occupies
Explanation:
Single dimension is a laminar
Amount of 2 dimension is area
Amount of 4 dimension is negligible
[tex].[/tex]
Answer C. Amount of 3 dimensional space the object occupies
Explanation:
Single dimension is a laminarAmount of 2 dimension is areaAmount of 4 dimension is negligible
3. Take vinegar, lemon juice, tap water in three separate glass beakers. Put chalk piece,pin, egg shell, leaves in three beakers. Note your observations how test the gas evolved in it.
Answer:
This process is know as Chromotography
Explanation:
i need help please........
Answer:
cd
Explanation:
image is formed due to reflected light rays and it is enlarged because image distance/ object distance = height of image/height of object
v>u so image is enlarged
Which of the following is NOT a pure substance?
а.
b.
C.
d.
Answer:
lol where is your questions??
Help!! due tomorrow
.
Answer:
It's B. The molecules in the system have more kinetic energy than a solid.
Which of the following is an example of climate?
The polar regions have long winters and short, cool summers.
Humidity levels are high today.
Canada experienced an unusually warm summer this year.
Tornados formed across Oklahoma yesterday.
Answer:
"The polar regions have long winters and short, cool summers."
Explanation:
Climate is the average of that weather. The climate record also includes extreme values such as record high temperatures or record amounts of rainfall.
For Climate example:
You can expect snow in the Northeast in January or for it to be hot and humid in the Southeast in July.
Freezing water cracking limestone
a
Chemical Change
b
Physical Change
Answer:
Freezing water and cracking limestone are physical changes.
has a density of 0.855 g/mL. How many LITERS would have a mass of 1.00 kg?
Answer:
V = 1.154 L
Explanation:
1. convert 1.00 kg to grams = 1,000 grams
2. use density formula d = m/v to find volume
v = m/d = 1,000 g = 1,154.73 ml
0.866 g/mL
convert to liters, divide by 1000 ml
V = 1.154 L
When a gas is dissolved in a liquid, what happens when the pressure increases?
Answer: B, the gas is being squeezed out of the liquid.
Explanation: The gas does not want to be trapped inside of the liquid, so it is trying to force it’s way out. Therefore creating more pressure in the container or whatever the liquid is being held in.
Answer: more gas dissolves into the liquid
Explanation: just got it wrong thats the right answer
how could you use this procedure to identify
as unknown type of green ink?
Answer:
After conducting the experiment it was clear to see that the green ink used was indeed a mixture as it separated from the rubbing alcohol.
Which of the following
statements is true about the
charges of protons and neutrons?
A. Protons and neutrons have the same charge.
B. Protons have a positive charge and neutrons
have no charge.
C. Protons have a negative charge and neutrons
have a positive charge.
Answer:
B
Explanation:
Protons have a positive charge while neutrons have no charge because they are neutral.
Answer:
b
Explanation:
b/ce protons have+ charge while neutrons have no charge
Can lead ii carbonate conduct electricity? Explain your answer
Solid Lead II carbonate can not conduct electricity because it is insoluble in water.
First of all, we must establish the fact that ionic solids conduct electricity in solution because they can be broken up into ions in solution.
In the solid state, they do not conduct electricity because the ions are strongly bound by electrostatic forces.
However, if an ionic substance is insoluble in water, its ions are not available to conduct electricity since ions are the charge carrier in solution. As a result of this, such a substance will not conduct electricity.
Since Lead II carbonate is insoluble in water, its ions are not available hence the substance does not conduct electricity.
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why is chromatography not able to separate components of a solution which have same speed?Give reason.
Answer:
The dyes which cover more surface area will travel more slowly. Similarly if two substances which have same speeds, they are going to travel together and they won't separate as chromatography separates substances having different rates or speeds for travelling
Chromatography cannot separate components with the same speed due to their identical affinities.
Why does chromatography fail to separate components with similar speeds?In chromatography, separation relies on differences in affinity between the components and the stationary phase. When components have the same speed, it indicates that their interactions with the stationary phase are nearly identical.
As a result, the forces that cause one component to move ahead of the other are not pronounced enough to achieve effective separation. Without distinct interactions, chromatography struggles to discriminate between components leading to poor separation outcomes.
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on what factors the Modern Periodic Table is different from that of the Mendeleev's periodic table?Write any two reasons.
Explanation:
The main difference between Mendeleev and Modern period table is that Mendeleev's periodic table orders the elements based on their atomic mass whereas Modern periodic table orders the elements based on their atomic number.
Mendeleev's periodic law states that the physical and chemical properties of the elements are a periodic function of their atomic weights while Modern periodic law states that physical and chemical properties of elements are a periodic function of their numbers.
How can you determine the number of shells in an atom of a certain element, based
on the element's position on the periodic table?
Answer: At some point in your chemistry education, you may have been introduced to the song “The Elements in which Tom Lehrer does a rapid
fire musical rendition of all the elements' names. Like me, you may even have been offered the opportunity to memorize this song for extra credit. If so, it’s possible that you still remember the names of all the elements, which is an impressive feat—not to mention a fun trick to pull out at parties.
Explanation:
The phenomenon where an electric current is produced by shining a light on a metal plate is called the ________ effect. The minimum frequency required to cause to flow is called the ________ frequency. This frequency depends on the identity of the metal used.
Answer:
Photoelectric, Threshold
Explanation:
Your welcome
What is the relationship between a calorie and a
joule?
In comparing groups, the first or the second, which group was more precise or was the precision the same
Comparing the data obtained online, the first group is more precise
The reason the above selection is correct is as follows;
Question: Parts of the question appear missing from a similar question online and included here;
First Group:
[tex]\begin{array}{|c|c|c|c|c|c|c|} Team \ a &Team \ b&Team \ c&Team \ d&Team \ e&Team \ f&Team \ g\\2.77 \ cm&2.60 \ cm&2.80 \ cm&2.65 \ cm&2.75 \ cm&2.65 \ cm& 2.68 \ cm\end{array}\right][/tex]
Second Group
[tex]\begin{array}{|c|c|c|c|c|c|c|} Team \ a &Team \ b&Team \ c&Team \ d&Team \ e&Team \ f&Team \ g\\2.70 \ cm&2.78 \ cm&2.62 \ cm&2.65 \ cm&2.75 \ cm&2.80 \ cm& 2.60 \ cm\end{array}\right][/tex]
Calculations for the first group:
The average = (2.77 + 2.60 + 2.80 + 2.65 + 2.75 + 2.65 + 2.68)/7 = 2.7
The range = 2.80 - 2.60 = 0.20
The approximate ± range of the average = ±0.2/2 = ±0.1
The precision of the first measurement is 2.7 ± 0.1 cm
Calculations for the second group:
The average = (2.70 + 2.78 + 2.62 + 2.65 + 2.75 + 2.80 + 2.60)/7 = 2.7
The range = 2.80 - 2.60 = 0.20
The approximate ± range from the average = ±0.2/2 = ±0.1
The range of values from the average is approximately ±0.1 cm
The precision of the first measurement is 2.7 ± 0.1 cm
Method to determine precision:
Precision is given by the finding the average deviation and the standard deviation as follows;
[tex]\mathbf{Average \ deviation} = \dfrac{\sum \left | x - \mu \right |}{n}[/tex]
[tex]\mathbf{Standard\ deviation} =\sqrt{\dfrac{\sum \left ( x - \mu \right )^2}{n}}[/tex]
Where;
μ = The mean or average = 2.7
n = The number of items (count) of the data = 7
For the first group, we have;
[tex]\mathbf{\dfrac{\sum \left | x - \mu \right |}{n}} = \dfrac{0.07 + 0.1 + 0.1 + 0.05 + 0.05 + 0.05 + 0.02 }{7} = \mathbf{0.062857}[/tex]
The average deviation of the first group = 0.062857
∑(x - μ)² ≈ 0.0328
[tex]\mathbf{The \ standard\ deviation} =\sqrt{\dfrac{0.0328}{7}} \approx \mathbf{0.068452}[/tex]
For the second group, we have;
[tex]\mathbf{\dfrac{\sum \left | x - \mu \right |}{n}} = \dfrac{0.0+ 0.08 + 0.08 + 0.05 + 0.05 + 0.1 + 0.1 }{7} = \mathbf{0.06571428571}[/tex]
∑(x - μ)² ≈ 0.0378
[tex]\mathbf{The \ standard\ deviation} =\sqrt{\dfrac{0.0378}{7}} \approx \mathbf{0.073485}[/tex]
By using the average deviation, and standard deviation values, the deviation of the second group is more than the first group and therefore the first group is more precise
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Why is copper sulfate a compound and diamond an element?
Answer:
Copper(II) sulfate is the chemical compound with the formula CuSO4. This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue.
Explanation:
Answer:
Copper sulfate is the compound with the formula CuSO4. This salt exists as a series of compounds that differ in their degree of hydration. The anhydrous form is a pale green or gray-white powder, whereas the pentahydrate (CuSO4·5H2O), the most commonly encountered salt, is bright blue.Yes, Diamond is called as an element because it is a crystalline form of a single element i.e., carbon. The structure of Diamond is cubic type, in which one carbon atom is tetrahedrally bonded to four other carbon atoms. This tetrahedral structure is extended in all three directions.Explanation:
I hope U like my answer and my answer helped U....Explain briefly why ammonia and oxygen molecules participate readily in coordinate bonding. Give an example for the formation of an ion by ammonia by this means. Show by means of electronic diagram the formation of a coordinate linkage between phosphorus tri chloride and oxygen?
Explanation:
When one atom supplies both electrons in forming a two-electron bond, it is known as a dative covalent or coordinate bond. ... In this case, the nitrogen atom has a lone pair of electrons that coordinates to the hydrogen cation, which has zero electrons, forming a covalent bond.
What does PA signify? How does it differ from 4P?
Answer:the snaswer is combined
Explanation:you have to piutg it’s toggle did dcdhcd
WHATS THE FREEZING POINT FOR WATER
Answer:
0 degrees Celcius and 32 degrees fahrenheit
Explanation:
A researcher wants to conduct an experiment to see how the amount of breakfast a student eats
affects their performance in school. He makes 2 groups, one group consumes 300 calories in
the morning while the second group does not eat breakfast at all. After 2 weeks he compares
the students test scores and every student takes the same tests. Identify the following:
a. Control Group:
b. Independent Variable:
c. Dependent Variable:
The control group are the students who eat no breakfast. The independent variable is the consumption of breakfast. The dependent variable is the performance of students in school.
In an experiment, the control group is the group that did not receive the treatment. The treatment in this case is the consumption of breakfast. Hence the group that did not consume breakfast is the control group.
The independent variable is the variable that is being manipulated and its effect evaluated. The manipulated variable here is consumption of food.
The dependent variable is the variable that is being measured. In this case, it is the performance of students at school.
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