1.as you move from left to right across a period, the number of valence electrons
-increases
-stays the same
-increases and then decreases
-decreases

2.compared with group 2a elements, group 64 elements have
-more atoms in the ground state
-more valence electrons
-more isotopes
-fewer valance electrons

3.which of the following group 7a elements is the most reactive?
-ci(chlorine
-i(iodine)
-f(fluorine)
-br(bromine)

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.

jjj89t'ji; it hink the answer is your mom is not si