The number of bonds an atom can form without violating the octet rule is reflected in the number of holes the "ball" for that atom has in the ball-and-stick model set. Based on that information, how many holes would you expect to see in models of atoms for each of the following elements: (4 points total; 1 point per element) a. Carbon (C)

four holes

Explanation:

A ball and stick model is a representation of a molecule that can show the number of bonds and sometimes, the stereochemistry of the molecule under study.

The number of holes on present in the ball and stick model for any atom corresponds to the number of bonds that particular atom can form without violating the octet rule.

Carbon is usually tetravalent, it forms four bonds to other atoms. Hence we expect carbon to have four holes.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.