Question

question 19 (5 points)
which of the following is an example of a physical property?
o a reactivity with acid
b flammability
o c ability
d boiling point

question 20 (5 points)
accoding to the the amount of mass after a chemical reaction.
o a physical properties; stays the same
b law on conservation of mass; stays the same
o c chemical properties; increases
d law of conservation of mass; increases

Explanation:

• Question 19: Physical properties can be observed or measured without changing the substance's chemical identity. Reactivity with acid (a) and flammability (b) involve chemical changes. "Ability" (c) is too vague. Boiling point (d) is a physical property as it describes a state change (liquid to gas) without altering the chemical structure.
• Question 20: The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. Physical properties (a) are not relevant here. Chemical properties (c) don't govern mass conservation. The law of conservation of mass means mass stays the same, not increases (d). So, the law of conservation of mass (b) is correct.

Answer:

• Question 19: d. boiling point
• Question 20: b. law on conservation of mass; stays the same