Which of the following is a physical property of the salt crystals shown here? A. they are gas
B. they cannot burn
c. they are a liquid
D. they are clear white

As the explanation i think the answer is D

Explanation:

Transparent and colourless in crystalline form – rather like ice. Crystallises in the isometric system, usually in the form of cubes. Soluble in water (35.6g/100g at 0°C and 39.2g/100g at 100°). Slightly soluble in alcohol, but insoluble in concentrated hydrochloric acid.Physical properties: Sodium chloride is a white crystalline solid with a density of 2.16 g/mL, and a melting point of 801 °C. It is also available as aqueous solutions of different concentrations, called saline solutions. Chemical properties: Sodium chloride is readily soluble in water and other polar solvents.

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.

yes the answer is total mass in unchanged   : )