<span>C. New substances are always produced in chemical changes, which is not the case with physical changes. For example, when you cut wood into smaller pieces you still have wood in the end. But, with a chemical change you change the substance's whole composition. For example when you add two hydrogen's to one oxygen you have water and it can't break down from that. </span><span />
Answer:
The C. Heat
Explanation:
It is logical, when you workout you feel hot cause your body emanates heat
The answer is: both choices a and b.
The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).
For example, the molar mass of fluorine is 38.00 g/mol.
M(F₂) = 2 · Ar(F) · g/mol.
M(F₂) = 2 · 19.00 · g/mol.
M(F₂) = 38.00 g/mol.
Molar mass M represent the mass of a substance (in this example molecule of florine) divided by the amount of substance.
Ar is the atomic weight of a chemical element (in this example fluorine).
Answer:
19 g
Explanation:
Data Given:
Sodium Chloride (table salt) = 50 g
Amount of sodium (Na) = ?
Solution:
Molecular weight calculation:
NaCl = 23 + 35.5
NaCl = 58.5 g/mol
Mass contributed by Sodium = 23 g
calculate the mole percent composition of sodium (Na) in sodium Chloride.
Since the percentage of compound is 100
So,
Percent composition of sodium (Na) = 23 / 58.5 x 100
Percent of sodium (Na) = 39.3 %
It means that for ever gram of sodium chloride there is 0.393 g of Na is present.
So,
for the 50 grams of table salt (NaCl) the mass of Na will be
mass of sodium (Na) = 0.393 x 50 g
mass of sodium (Na) = 19 g
