the atomic number of four elements p, q,r, s are 6,8,10 and 12 respectively. the two elements which can bond ionically are:

The atomic numbers of four elements A, B, C, and D are 6,8,10, and 12 respectively. The two elements which can react to form ionic bonds (or ionic compounds) are B (8= 2,6) and D (12 =2,8,2). So D donates its two electrons to B to fulfill their octet.

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.