30 points and i will give brainliest!

CaCl2

The charge can be +3 or +2

Explanation:

It takes two atoms of chloride and 1 atom of calcium to make this compound

chemical formula is CaCl2.

CaCl2> Ca^2+ + Cl^-1

Explanation:

+2 for calcium ion and -1 for the chlorine ion.

For K2Cr2O7

The oxidation state of chromium=

(+1×2) + 2x + (-2×7) = 0

+2+2x-14= 0

2x= 12

x= 12/2

x=+6.

Therefore, the oxidation number of Chromium, Cr in K2CrO7 is +6

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).