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3 years ago

How do you calculate the number of valence electrons in an atom?

1 answer:

5 0

To find the valence electrons in an atom, identify what group the element is in. An element in group 1A has 1 valence electron. For example, Li is in group 1A, so that means it has one valence electron. If the element is in group 2A, then it has two valence electrons.

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A student claims that if she wanted to make a solution quickly, she should use small pellets instead of powder along with heatin

vova2212 [387]

Answer: Yes we agree with the student's claim.

Explanation:

When the molecules are present in smaller size, more reactants can react as decreasing the size increases the surface area of the reactants which will enhance the contact of molecules.Hence, more products will form leading to increased rate of reaction.

On increasing the temperature will make more reactant molecules will have sufficient energies to cross the energy barrier and thus the number of effective collisions increases, thus leading to more products and increased rate of reaction.

When the solution is stirred , the molecule's kinetic energy and thus the rate of reaction increases.

Thus smaller size, stirring and increase of temperature will make the solution quickly.

7 0

3 years ago

Which of the following is true about two neutral atoms of the element gold? (1 point) The nucleus is missing in both. Each has a

klio [65]

i have the same question idk the anwser tho

5 0

3 years ago

Which of these elements is unlikely to have a reaction with any element or compound?

Kay [80]

Argon is a noble gas. Argon has a full outer shell. This makes it so that it does not need to react with any of the other elements to be stable.

With Rubidium and Cobalt its a whole different story.

I hope that helps!

8 0

3 years ago

Iron is biologically important in the transport of oxygen by red blood cells from the lungs to the various organs of the body. I

Aneli [31]

Answer : The number of iron atoms present in each red blood cell are, $1.077\times 10^9$

Explanation :

First we have to calculate the moles of iron.

$\text{Moles of iron}=\frac{\text{Mass of iron}}{\text{Molar mass of iron}}=\frac{2.90g}{55.85g/mole}=0.0519moles$

Now we have to calculate the number of iron atoms.

As, 1 mole of iron contains $6.022\times 10^{23}$ number of iron atoms

So, 0.0519 mole of iron contains $0.0519\times 6.022\times 10^{23}=3.125\times 10^{22}$ number of iron atoms

Now we have to calculate the number of iron atoms are present in each red blood cell.

Number of iron atoms are present in each red blood cell = $\frac{\text{Number of iron atoms}}{\text{Total number of red blood cells}}$

Number of iron atoms are present in each red blood cell = $\frac{3.125\times 10^{22}}{2.90\times 10^{13}}$

Number of iron atoms are present in each red blood cell = $1.077\times 10^9$

Therefore, the number of iron atoms present in each red blood cell are, $1.077\times 10^9$

6 0

3 years ago

We have two surfaces A and B where same amount of Force is acting. Area of Surface A is greater than Area of Surface B. which of

Phoenix [80]

Answer:

Pressure on Surface A > Pressure on Surface B

Explanation:

Pressu

re on Surface B > Pressure on Surface A

7 0

3 years ago