Elements and Atomic Structure

Question 1

1. What is a pure substance?
2. What is an impure substance?

Answer 1

1. A pure substance consists of only one kind of particle. It has a fixed melting point.
2. An impure substance is a kind of mixture. It melts over a broader range of temperatures, lower than the pure substance.

Question 2

What are the mass and charge of a proton, neutron and electron?

Answer 2

Proton - Mass 1, Charge +1
Neutron - Mass 1, Charge 0
Electron - Mass 1/1836, Charge -1

Question 3

1. How do you calculate the number of protons?
2. How do you calculate the number of electrons?
3. How do you calculate the number of neutrons?

Answer 3

1. The atomic number (bottom)
2. The number of protons = the number of electrons
3. Mass number (top) - Atomic number (bottom)

Question 4

Why are all elements neutral?

Answer 4

They have the same number of protons and electrons so the charge cancels out

Question 5

What is an isotope?

Answer 5

Atoms of the same element that have the same atomic number (protons) but a different mass number (neutrons)

Question 6

Why do all isotopes of the same element react in the same way?

Answer 6

They have the same number of electrons (electrons affect chemical reactions).

Question 7

How do you calculate the relative atomic mass of an isotope (Mr)?

Answer 7

Relative atomic mass = (Mass of atom 1 X % of Atom 1) + (Mass of atom 2 X % of atom 2) /100

Question 8

How many electrons go in each shell (up to 4 shells)?

Answer 8

2,8,8,8

Question 9

Which atoms are diatomic?

Answer 9

Group 7, N, O & H

Question 10

Why do noble gases not react?

Answer 10

They have full outside shells.

Question 11

What are 3 differences between metals and non-metals?

Answer 11

Metals - High melting and boiling points, Malleable, Good conductors
Non metals - Low melting and boiling points, Brittle, Non-Conductors

Question 12

Metal oxides are ____ - Acidic or Basic (Alkali)?
Non-Metal oxides are ___ - Acidic or Basic (Alkali)?

Answer 12

Metal oxides are acidic
Non-metal oxides are basic (Alkali)

Question 13

What is the difference between -ide and -ate endings?

Answer 13

-ide - Contains just the elements in the compound
-ate - Contains the elements in the compound and oxygen

Question 14

How do you write formula from the elements

Answer 14

Swap and drop method using valency. (You must simplify)

Question 15

How do you balance equations?

Answer 15

Make sure both sides have the same amount of all elements.