Please help me, thank you in advance :) Have a great day/night <3
(There's 4 questions)

Match the element with its description.

Elements:

1. Fluorine
2. Lithium
3. Krypton
4. Lead

descriptions:

a. Malleable, soft, and shiny
b. Opaque solid with higher density
c. Highly reactive gas
d. Nonreactive gas

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.