Answer;
-4. metallic, because the valance electrons are mobile
Explanation;
-Electrical conductivity in metals is a result of the movement of electrically charged particles.The atoms of metal elements are characterized by the presence of valence electrons (electrons in the outer shell of an atom) that are free to move about.
-Therefore; Metallic elements such as sodium and potassium conducts electricity in solid form due to the presence of delocalized valence electrons. These electrons can move freely within the structure of a metal when an electric current is applied.

The 2 in front of
in
is <u>Coefficient.</u>
_____________________________
The
after
in the same equation is <u>sub </u><u>script</u><u>.</u>
_____________________________
There are two atoms of
in 
_____________________________

Answer:
D. Black Holes
Explanation:
Black holes are large objects that form dense gravity wells in space. Their gravitational pull is so strong that even light cannot escape it.
Answer:
The value of y = 5.1478
Explanation:
The linear equation is an equation obtained when a linear polynomial is equated to zero. When the solution obtained on solving the equation is substituted in the equation in place of the unknown, the equation gets satisfied.
The given equation: 5.3 x 10- (y)(2y) = 0
⇒ 53 - 2y² = 0
⇒ 2y² = 53
⇒ y² = 53 ÷ 2 = 26.5
⇒ y = √26.5 = 5.1478
Molarity is a concentration unit, defined to be the number of moles of solute divided by the number of liters of solution.