Nitrogen is a group 15 element. what does being in this group imply about the structure of the nitrogen atom ?

All Group 15 elements tend to follow the general periodic trends:

Electronegativity (the atom's ability of attracting electrons) decreases down the group.

Ionization energy (the amount of energy required to remove an electron from the atom in its gas phase) decreases down the group.

Atomic radii increase in size down the group.

Electron affinity (the ability of the atom to accept an electron) decreases down the group.

Melting point (amount of energy required to break bonds to change a solid phase substance to a liquid phase substance) increases down the group.

Boiling point (amount of energy required to break bonds to change a liquid phase substance to a gas) increases down the group.

Metallic character increases down the group.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles