Unit Two: Atoms and Compounds

Question 1

What is the mass number (in an atom)?

Answer 1

The total of protons and neutrons

Question 2

What is the atomic number (in an atom)?

Answer 2

The number of protons

Question 3

What is a compound?

Answer 3

Compounds are formed when atoms of two or more elements are chemically combined together

Question 4

What is an isotope?

Answer 4

Different atomic forms of the same element, which have the same number of protons but a different number of neutrons

Question 5

What is ionic bonding?

Answer 5

In ionic bonding, atoms lose or gain elections to form charged particles (called ions) which are then strongly attracted to one another (+ and -)

Question 6

Why do shells with just one or two electrons want to get rid of them?

If they get rid of them, what are they left as?

Answer 6

Because they want full shells (they try to have the same electronic structure as a noble gas)

Ions

Question 7

Why do atoms with shells that are nearly full want an extra electron?

Answer 7

To have a full outer shell so they become ions

Question 8

What do ionic compounds always have?

What do they have?

Answer 8

Giant ionic lattices-a closely packed regular lattice arrangement

Very strong electrostatic forces of attraction between oppositely charged ions

Question 9

What similarities do all ionic compounds have?

Answer 9

High melting points and high boiling points due to the strong attraction between ions

They dissolve easily in water as the ions separate and are free to move

Question 10

Ionic compounds:

Answer 10

Ionic compounds are made up of a positively charged part and a negatively charged part

The overall charge of any compound is zero

So all - charges balance all the + charges