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3 years ago

How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight

Chemistry

1 answer:

Lera25 [3.4K]3 years ago

6 0

Answer:

Explanation:

Noble gases are the least reactive of all known elements. That's because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons.

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What is the molar mass of Mg(NO2)2?

qwelly [4]

Answer:

116g/mol

Explanation:

Mg=24

NO2=46

multiple 46 by 2and then add 24

3 0

3 years ago

How many moles of hydrogen are in the sample? Round your answer to 4 significant digits.

finlep [7]

Answer:

1.56 mol H₂

Explanation:

Mg₃(Si₂O₅)₂(OH)₂

There are 4 Si moles per Mg₃(Si₂O₅)₂(OH)₂ mol. With that in mind we can calculate how many Mg₃(Si₂O₅)₂(OH)₂ moles are there in the sample, using the given number of silicon moles:

3.120 mol Si * $\frac{1molMg_3(Si_2O_5)_2(OH)_2}{4molSi}$ = 0.78 mol Mg₃(Si₂O₅)₂(OH)₂

Then we can convert Mg₃(Si₂O₅)₂(OH)₂ moles into hydrogen moles, keeping in mind that there are 2 hydrogen moles per Mg₃(Si₂O₅)₂(OH)₂ mol:

0.78 mol Mg₃(Si₂O₅)₂(OH)₂ * 2 = 1.56 mol H₂

8 0

3 years ago

The brand names used on del monte, pillsbury, harley-davidson, and purina products are called _____ brands because of who owns t

patriot [66]

Manufacturers Is Your Answer

4 0

3 years ago

Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Al(C2H3O2)3 and LiNO3 are mixed. Giv

RSB [31]

Answer: No reaction occurs

Explanation:.

Spectator ions are defined as the ions which does not get involved in a chemical equation or they are ions which are found on both the sides of the chemical reaction present in ionic form.

The given chemical equation is:

$Al(C_2H_3O_2)_3(aq)+3LiNO_3(aq)\rightarrow Al(NO_3)_3(aq)+3LiC_2H_3O_2(s)$

The complete ionic equation is;

$Al^{3+}(aq)+3C_2H_3O_2^-(aq)+3Li^+(aq)+3NO_3^-(aq)\rightarrow Al^{3+}(aq)+3NO_3^-(aq)+3Li^+(aq)+3C_2H_3O_2^-(aq)$

The ions which are present on both the sides of the equation are are not involved in net ionic equation.

Hence, there is no net reaction.

5 0

3 years ago

In a very violent reaction called a thermite reaction, aluminum metal reacts with iron (III) oxide to form iron metal and alumin

leva [86]

Here's the equation:
Fe2 O3 + 2Al → 2Fe + Al2 O3

Here's the question.
What mass of Al will react with 150g of Fe2 O3?

In every 2 moles Al you need 1 mole Fe2O3 

moles = mass / molar mass 
moles Fe2O3 = 150 g / 159.69 g/mol 
= 0.9393 moles 

moles Al needed = 2 x moles Fe2O3 
= 2 x 0.9393 mol 
= 1.879 moles Al needed 

mass = molar mass x moles 
mass Al = 26.98 g/mol x 1.879 mol 
= 50.69 g 
= 51 g (2 sig figs)

So the mass of Al that will react with 150g of Fe2 O3 is 51 grams.

3 0

3 years ago

How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight​

How many electrons are there in the only energy level of helium, a noble gas? * Two Three Six Eight