I've got a couple of chemistry questions.?

Question

1) An atom is 10 to the power of -10 m in diameter. How many would fit in a line across a pin head 0.1mm wide?

2) What property does the number of electrons in the outer shell govern?

3) What is the name of group 2 of the periodic table? ( I thought it was alkaline metals, but I can't find a periodic table with the names on)

4) What keeps electrons attracted to the nucleus? (Is it because they are negative but the nucleus is positive? That's what I thought but I'm not sure)

Thanks.

Answer 1

1/

10^ -10m =  0.000000001m

0.1mm = 0.0001m (1000 mm in a Meter, so divide by 1000)

0.001m / 0.000000001m = 100,000

So 100,000 atoms of size 10^ -10m would fit in a line 0.1mm wide

2/

The number of electrons on the outer shell of an atom determines what other atoms/ molecules will react with it (if any). This is called its "Valency". A complete outer shell will make a particle unreactive (inert, e.g all the noble gases in group 0), where as a particle that only needs 1 electron, or needs to "remove" an electron to get a complete shell are the most reactive.

3/

Alkaline earth metals

4/

Yes, the negitivly charged electrons are attracted to the positivly charged Protons. Neutrons have no charge so they don't effect it.

Answer 2

1) 100,000 atoms

2) chemical bonding

3) alkali earth metals

4) Coulomb's Law - the law of electrostatic force (like charges repel, opposite charges attract)