A chemist weighed out 19.9 g of aluminum. Calculate the number of moles of aluminum she weighed out.

Which of the following atoms would gain two electrons to fill its valence energy level?

Harlamova29_29 [7]

The atom that would gain two electrons to fill its valence energy level is S(sulfur)

This is because s (sulfur) is in atomic number 16 with 2.8.6 of [Ne] 3s^2 2p^4 electronic configuration. This implies that sulfur has 6 valence electron and therefore it require two electron to fill its valence energy level and obtain 18 rule electrons.

5 0

3 years ago

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The diameter of a biscuit is approximately 51 millimeters (mm). An atom of bismuth (Bi) is approximately 320. picometers (pm) in

astraxan [27]

Answer:

1.5e+8 atoms of Bismuth.

Explanation:

We need to calculate the <em>ratio</em> of the diameter of a biscuit respect to the diameter of the atom of bismuth (Bi):

$\\ \frac{diameter\;biscuit}{diameter\;atom(Bi)}$

For this, it is necessary to know the values in meters for any of these diameters:

$\\ 1m = 10^{3}mm = 1e+3mm$

$\\ 1m = 10^{12}pm = 1e+12pm$

Having all this information, we can proceed to calculate the diameters for the biscuit and the atom in meters.

<h3>Diameter of an atom of Bismuth(Bi) in meters</h3>

1 atom of Bismuth = 320pm in diameter.

$\\ 320pm*\frac{1m}{10^{12}pm} = 3.20*10^{-10}m$

<h3>Diameter of a biscuit in meters</h3>

$\\ 51mm*\frac{1}{10^{3}mm} = 51*10^{-3}m = 5.1*10^{-2}m$

<h3>Resulting Ratio</h3>

How many times is the diameter of an atom of Bismuth contained in the diameter of the biscuit? The answer is the ratio described above, that is, the ratio of the diameter of the biscuit respect to the diameter of the atom of Bismuth:

$\\ Ratio_{\frac{biscuit}{atom}}= \frac{5.1*10^{-2}m}{3.20*10^{-10}m}$

$\\ Ratio_{\frac{biscuit}{atom}}= \frac{5.1}{3.20}\frac{10^{-2}}{10^{-10}}\frac{m}{m}$

$\\ Ratio_{\frac{biscuit}{atom}}= 1.5*10^{-2+10}$

$\\ Ratio_{\frac{biscuit}{atom}}= 1.5*10^{8}=1.5e+8$

In other words, there are 1.5e+8 diameters of atoms of Bismuth in the diameter of the biscuit in question or simply, it is needed to put 1.5e+8 atoms of Bismuth to span the diameter of a biscuit in a line.

6 0

3 years ago

Energy is added in the form of heat to a pot of water on the stove. This causes the water to

Monica [59]

The energy would increase

b) increase kinetic energy

4 0

2 years ago

Which statement correctly compares the masses of subatomic particles in an atom such as carbon?

iogann1982 [59]

Answer:

C- A proton has about the same mass as a neutron .

Explanation:

In an atom such as a carbon atom, the masses of the proton and neutrons are the same.

The mass of the electrons is very negligible.

Protons are the positively charged particles in an atom
Neutrons do not carry any charges
Both protons and neutrons have similar masses.
They contribute the bulk of the mass of the atom.
The electrons carry negative charges and they have negligible masses.

The mass of protons and neutrons are similar.

5 0

2 years ago

How many grams are in 1.946 moles of nacl

Ilia_Sergeevich [38]

Answer:

113.8g

Explanation:

Statement of problem: mass of 1.946mole of NaCl

Given parameters:

Number of moles of NaCl = 1.946mole

Unknown: mass of NaCl

Solution

To find the mass of NaCl, we apply the concept of moles which expresses the relationship between number of moles and mass according to the equation below:

Number of moles = $\frac{mass}{molar mass}$

To find the molar mass of NaCl:

the atomic mass of Na = 23g

atomic mass of Cl = 35.5g

Molar mass of NaCl = (23 + 35.5) = 58.5gmol⁻¹

Mass of NaCl = Number of moles x molar mass of NaCl

Mass of NaCl = 1.946 x 58.5 = 113.8g

7 0

2 years ago