Read the summary below. Choose the answer that BEST goes into the blank to complete the summary The sun is a yellow dwarf star that lies in the center of our solar system, composed mainly of hydrogen and helium.
The energy produced in the sun's core provides almost all the heat and light necessary for life on Earth
The parts of the sun near the equator complete one rotation every 36 days
The sun is divided into several layers with a dense core and a surface consisting of gas and plasma
The yellow dwarf star is one of several kinds of stars, but is the most common star in the Milky Way
galaxy
(D)
Gravitational pull from the sun causes the matter in the sun to become more tightly packed, producing
energy

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

c. electrical charges of ionic bonds.