3. Why do elements in group 1-17 react to form bonds?

Elements in the same group of the periodic table have the same number of valence electrons. These are the electrons in their outer energy level that can be involved in chemical reactions. ... All the elements in group 1 have just one valence electron. This makes them very reactive.

Explanation:

a: 45.9 meters

b: 4.29 seconds

step-by-step explanation:

a: h(t)=1/2(-9.8)(3)^2+0(3)+90

h(t)=-4.9(3)^2+90

h(t)=-44.1+90

h(t)=45.9 meters

b: 0=1/2(-9.8)(t^2)+0t+90

0=-4.9t^2+90

-90=-4.9t^2

18.37=t^2

t=4.29 seconds

in the second question, the numbers aren't exact, but they're a close approximation.