PLEASE HELP 2. The elements in each have the same number of or .
3. Each column in the periodic table is called a .
4. Each of the elements in the same have the same number of in their outer shell.
5. The electrons in the outer shell are called electrons.
6. The number tells you the of electrons.​

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.

the ratio of the conjugate base to the acid required to attain the desired ph.