Can I get help on this please

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.

oxygen, selenium, tellurium, and polonium.

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

a electronegativity decreases beacuse the size of nucleus is bigger.

i think it's c. if you look search electronic symbol on google and then click on wiki it shows you a