What is the mass percent of sodium in nacl?
a)39.34%
b)60.66%
c)60.66%
d)78.68%

Explanation:

Molecular mass of NaCl = 58.44g/mol

Molecular mass of Na = 22.98g/mol

Molecular mass of Cl = 35.5g/mol

To find the percentage mass of Na in NaCl we divide the molecular mass of Na by the total number of atoms of Na present in the compound which in this case is 1 by the molecular mass of the compound

%Na = molecular mass of Na / molecular mass of compound.

%Na =( 22.98 / 58.44 ) * 100

% Na = 0.3932 * 100 = 39.32%

The mass percent of Na present in NaCl is 39.32%

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

it would be a gas formation