Please help me with this question

What are atoms made up of

faltersainse [42]

Answer:

They are made up of electrons, neutrons and protons

Explanation:

3 0

3 years ago

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B. if 6.73 g of na2co3 is dissolved in enough water to make 250. ml of solution, what is the molar concentration of sodium carbo

BARSIC [14]

Answer:- $[Na_2CO_3]=0.254M$ , $[Na^+]=0.508 M$ , $[CO_3^2^-]=0.254M$

Solution:- We are asked to calculate the molarity of sodium carbonate solution as well as the sodium and carbonate ions.

Molarity is moles of solute per liter of solution. We have been given with 6.73 grams of sodium carbonate and the volume of solution is 250.mL. Grams are converted to moles and mL are converted to L and finally the moles are divided by liters to get the molarity of sodium carbonate.

Molar mass of sodium carbonate is 105.99 gram per mol. The calculations for the molarity of sodium carbonate are shown below:

$\frac{6.73gNa_2CO_3}{250.mL}(\frac{1mol}{105.99g})(\frac{1000mL}{1L})$

= $0.254MNa_2CO_3$

So, molarity of sodium carbonate solution is 0.254 M.

sodium carbonate dissociate to give the ions as:

$Na_2CO_3(aq)\rightarrow 2Na^+(aq)+CO_3^2^-$

There is 1:2 mol ratio between sodium carbonate and sodium ion. So, the molarity of sodium ion will be two times of sodium carbonate molarity.

$[Na^+]=2(0.254M)$ = 0.508 M

There is 1:1 mol ratio between sodium carbonate and carbonate ion. So, the molarity of carbonate ion will be equal to the molarity of sodium carbonate.

$[CO_3^2^-]=0.254M$

5 0

3 years ago

What is the charge of an atom after it gains an electron during the formation of a bond?

Alex_Xolod [135]

Answer:

D. One negative charge

Explanation:

During the formation of a bond, if an atom gains an electron, after that it will be left with a negative charge compared to the atom before the bond is formed. This is because in these types of bonds, which are ionic bonds, there is a transfer of electrons between atoms, there will be one or more atoms that yield electrons that will be captured by another and other atoms that gain them, and the difference of charges produced by this transfer of electrons, will cause the union to occur due to the attraction between electrostatic forces.

If you have a neutral atom before joining, and it gains an electron to form a bond, it will have one electron more than its initial state (in the initial state, the number of protons and electrons is the same, because the atoms they are electrically neutral), so having an extra electron will make it have a negative charge, since there will be a difference between the number of protons and electrons that the atom possesses. This is why the correct answer is D.

In the case of response A and B, the atom could only remain positively charged if it loses electrons, but as in this case it wins, they are not correct.

The answer C is also not correct because only one electron wins, so that it is left with two negative charges, it should gain two electrons during the bond formation.

7 0

3 years ago

Boron has an atomic mass of 10.811. What does this mean?

icang [17]

Answer:

Knowing that boron has an atomic mass of 10,811 means that all boron isotopes on average weigh 10,811 u.

Explanation:

The atomic mass of an atom is the mass of the atom measured in u (unified atomic mass unit), although we can also express it as Da (Dalton's unit)

Atomic mass refers to the average mass that all isotopes of that element have.

When we speak of isotopes we are referring to the element itself but with a different number of neutrons, which makes it modify its mass number.

6 0

2 years ago

Please help me with this! I'd appreciate it. Thanks so much! :D

Setler [38]

Answer:

It is the second option.

Explanation:

The conversion factor is:

I kPa = 7.50062 Torr.

3 0

3 years ago