Atoms and Ions

Question 1

What is the charge of a proton?

Answer 1

1

Question 2

What is the charge of an electron?

Answer 2

-1

Question 3

What is the charge of a neutron?

Answer 3

0

Question 4

What is the atomic number of an element?

Answer 4

It is the number of protons in the atom.

Question 5

Does an element have a overall charge?

Answer 5

no

Question 6

What do atoms consist of?

Answer 6

Protons, neutrons and electrons
The protons and neutrons are found in the nucleus
and the electrons are located in the shell surrounding the nucleus.

Question 7

What is the atomic mass on an element?

Answer 7

This is the average mass of the protons and neutrons

Question 8

For example, what is Fe?

Answer 8

Fe is the symbol for the element iron

Question 9

What is the valence shell?

Answer 9

The valence shell is the outermost shell of an atom, it contains the valence electrons

Question 10

How many electrons fill a shell?

Answer 10

Well the innermost shell of the atom can only hold two electrons, this must be filled first before any more can.
After the innermost shell has been filled the rest can hold a maximum of eight electrons.

Question 11

When is an atom stable?

Answer 11

An atom is stable if:

1. It has a full valence shell
2. It was a neutral overall charge (same amount of protons and electrons)

Question 12

How are ions formed?

Answer 12

Ions are formed when an atom either loses or gains electrons. This results in an atom that is charged which we call ions.

Question 13

What are cations?

Answer 13

Cations are positively charged ions caused by an atom losing electrons. (these are metals)

Question 14

What are anions?

Answer 14

Anions are negatively charged ions caused by an atom gaining electrons. (these are non-metals)

Question 15

When do atoms lose or gain electrons?

Answer 15

They lose or gain electrons depending on which requires the least energy. eg - moving two electrons requires less energy than moving six

Question 16

Does a cations name ever change?

Answer 16

No

Question 17

Does an anions name ever change?

Answer 17

Yes, they are given a specific suffix depending of whether they’re monoatomic or polyatomic

Question 18

What happens to a monoatomic anion?

Answer 18

Monoatomic ions are given the ‘ide’
(tip to remember - the ‘i’ stands for individual)
e.g, the fluorine ion is called fluoride

Question 19

What happens to a polyatomic anion?

Answer 19

Polyatomic anions are given ‘ate’
(tip to remember - the ‘a’ means add oxygen)
e.g, sulfate is an ion of sulfur and oxygen: SO₄²-

Question 20

What are the two ion names that are exceptions?

Answer 20

OH- is the anion hydroxide

NH₄⁺ is the cation ammonium

Question 21

What are transition metals?

Answer 21

Transition metals form more complex electron configurations and form multiple ions. These ions will have a roman numeral denoting their charge. 
e.g, Fe(II) is Fe²⁺ 
and Fe (III) is Fe³⁺

Question 22

What are cations attracted to?

Answer 22

Anions (and same vise-versa)

Question 23

What happens when cations and anions are together?

Answer 23

They form strong ionic bonds held together by electrostatic attraction between the two oppositely charged ions.

Question 24

What are ionic compounds?

Answer 24

An ionic compound is a chemical compound composed of ions held together by electrostatic forces.

Question 25

What must ionic compounds have?

Answer 25

A neutral overall charge. When ions have uneven charges we continue to add ions until the positive and negative charges balance.

Question 26

What ions are polyatomic?

Answer 26

Cation: Ammonium NH₄⁺ 
Anions: Hydroxide: OH−
Sulfate: SO₄²-
Nitrate:  NO₃⁻ 
Carbonate: CO₃²-
Hydrogen carbonate HCO₃⁻ 
(sometimes) Phosphate: PO₄³⁻

Question 27

What are the steps for writing about the formation of ionic compounds in NCEA?

Answer 27

Writing for NCEA: Formation of ionic compounds
Follow these steps:

1. For each ion:
   a. state the electron configuration of the atom.
   b. state how many electrons it will lose/gain to have a full valence shell.
   c. state the ion this will produce (name+symbol).
2. For the compound:
   a. state the number of cations and anions needed to make a neutral molecule. (e.g 1 calcium ion (total charge: Ca2+) and 2 chloride ions (Total charge Cl-) are required to produce a neutral molecule)
   b. state the total charge of the cations and anions (if balancing is needed).
   c. state the formula of the compound.

Question 28

What is the law of the conservation of mass?

Answer 28

During a chemical reaction, atoms cannot be created or destroyed. They can only be rearranged.

Question 29

How do you balance a chemical equation?

Answer 29

The atoms on the left-hand side of the reaction arrow must be the same as the atoms on the right-hand side.