<h2>The answers are

and

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Explanation:
Given -
a) The molecular formula of ethylene glycol -

∴ The empirical formula of ethylene glycol will be -

Given -
b) The molecular formula of per-oxo-disulfuric acid (a compound used in bleaching agents) -

∴ The empirical formula of per-oxo-disulfuric acid will be -

Hence, the answers are
and
.
Au (Gold) is an atomic element
Answer:
d = 14.9 g/mL
Explanation:
Given data:
Mass of metal = 22.4 g
Volume of eater = 3.2 mL
Volume of water + metal = 4.7 mL
Density of metal = ?
Solution:
Volume of metal:
Volume of metal = volume of water+ metal - volume of water
Volume of metal = 4.7 mL - 3.2 mL
Volume of metal = 1.5 mL
Density of metal:
d = m/v
d = 22.4 g/ 1.5 mL
d = 14.9 g/mL
Answer is: <span>The general rule of thumb is that the smaller a substance's atoms and the stronger the bonds, the harder the substance will be.
If the distance between atoms is higher, lesser will be attraction between electrons and protons of atoms, smaller distance means stronger atoms attraction.
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