Food that has been irradiated
Answer:
9.72 × 10^20 molecules
<h3>
Explanation:</h3>
We are given;
- The mass of the compound C16H18N2O4S as 540 mg
- Molar mass of C16H18N2O4S = 334.4 g/mol
We are required to determine the number of molecules in 540 mg of penicillin.
- We know that 1 mole of a compound contains molecules equivalent to the Avogadro's number.
- That is, 1 mole of a compound = 6.022 × 10^23 molecules
- Therefore, 1 mole of C16H18N2O4S = 6.022 × 10^23 molecules
But, 1 mole = 334.4 g
Thus, 334.4 g of C16H18N2O4S contains 6.022 × 10^23 molecules
Mass of C16H18N2O4S = 540 mg or 0.54 g
Molecules in 0.54 g will be;
= (0.54 g ÷ 334.4 g) × 6.022 × 10^23 molecules
= 9.72 × 10^20 molecules
Answer:-
A. A water molecule
Explanation:-
A molecule is the smallest particle of a compound that retains all it's chemical properties.
Here H2O is a compound. So the smallest particle that will retain all the chemical properties and still remain water is water molecule.
Atoms Hydrogen and Oxygen both have different chemical properties from water H2O and are thus different.
Hydrogen peroxide is different molecule from water. So it is also not water.
Answer:
4
Explanation:
The zeros before a non zero digit do not count as significant figures so there are 4 sig figs in the number