C1-Atomic Structure and Periodic Table

Question 1

What is the radius of an atom?

Answer 1

0.1 nanometres (1 x 10^-10m)

Reason of 10 being to power of -10 instead of -9 is because it is 0.1nm not 1nm.

Question 2

Describe the Nucleus of an atom

Answer 2

1) It’s in the middle of the atom
2)Contains Protons (+) and Neutrons (=)
3)Has a radius of around 1 x 10^-14m (around 1/10000 of the radius of an atom)
4) Positive charge bc of protons
5)Almost whole mass of atom is concentrated in nucleus

Question 3

Describe the Electrons in an atom

Answer 3

1)Move around nucleus in electron shells
2)Negatively charged and tiny, but cover a lot of space
3)Volume of their orbits determines size of atom
4)Electrons have virtually no mass

Question 4

State the relative mass and charge of:
-Proton
-Neutron
-Electron

Answer 4

-Proton has mass of 1 and charge of +1
-Neutron has mass of 1 and charge of 0
-Electron has mass of 0 (or very small) and charge of -1

Question 5

How come atoms are neutral (have no overall charge)? (Unlike ions)

Answer 5

They have the same number of protons as electrons.
This means the charges cancel out.

Question 6

What is an ion?

Answer 6

An ion is an atom or group of atoms that has lost or gained ELECTRONS, so is charged.
Number of protons≠Number of electrons.

Question 7

What does it mean if an ion has a charge of 2-?
Remember when writing charge of ions the + or - comes AFTER number.

Answer 7

That ion has two more electrons than protons

Question 8

What does it mean if an ion has a charge of 2-?
Remember when writing charge of ions the + or - comes AFTER number.

Answer 8

That ion has two more electrons than protons.

Question 9

What is the nuclear symbol of an atom?

Answer 9

The letters that are used as its place holder in the periodic table and its mass and atomic number. E.g.
23
Na
11

Question 10

What does the atomic number (bottom number) tell you?

Answer 10

How many protons there are

Question 11

What does the mass number (top number) tell you?

Answer 11

Total number of protons and neutrons in atom.

Question 12

How would you get number of neutrons from atomic number and mass number?

Answer 12

Subtract atomic number from mass number.

Question 13

Remember when writing in standard form

Answer 13

To not write 1nm as 1 x 10^-9nm!
Write it as 1 x 10^-9m as the prefix nano means 1 x 10^-9!

Question 14

Define an element

Answer 14

A substance made up of atoms that all have the SAME number of PROTONS in their nucleus.

Question 15

What are the symbols for these elements?
-Carbon
-Oxygen
-Sodium
-Iron

Answer 15

-Carbon=C
-Oxygen=O
-Sodium=Na
-Iron=Fe

Question 16

Define an isotope

Answer 16

Isotopes are different forms of the same element, which have the same number of protons(and electrons) but a different number of neutrons.

Question 17

What does this mean about the atomic and mass number of an isotope?

Answer 17

They have the same atomic number but a different mass number

Question 18

When talking about Isotopes, why is Ar used instead of the mass number when referring to the element as a whole?

Answer 18

Because many elements can exist as a number of different isotopes.

Question 19

What is Ar?

Answer 19

An average mass taking into account the different masses and and abundances (amounts) of all the isotopes that make up the element.

Question 20

How do you calculate Ar/relative atomic mass?

Answer 20

Ar= sum of (isotope abundance x isotope mass number)/ sum of abundances of all the isotopes

sum of (isotope abundance x isotope mass number) just means that you would do this for all of the isotopes present and then add the answers together.

Question 21

Are there any units for Ar?

Answer 21

Nope, just the number

Question 22

Define a compound

Answer 22

Compounds are substances formed from two or more elements which are chemically bonded (atoms are held together by chemical bonds)

Question 23

What does making bonds involve?

Answer 23

Atoms giving away, taking or sharing electrons.

Question 24

During a chemical reaction…

Answer 24

at least one new substance is made

Question 25

What does a compound which is formed from a metal and non-metal consist of and what is this bonding called?

Answer 25

It consists of ions, the metal atoms LOSE electrons to form + ions and non-metal atoms GAIN electrons to form - ions.
Metals always LOSE electrons, Non-metals always GAIN electrons.
This is called IONIC Bonding.

Question 26

How does ionic bonding work?

Answer 26

The opposite charges of the ions (positive and negative) mean they are strongly attracted to each other. The forces between these ions are strong electrostatic forces.

Question 27

A compound formed from two non-metals…

Answer 27

is a Covalent compound

Question 28

Describe the qualities of Fluorine

Answer 28

Very reactive, poisonous yellow gas

Question 29

Describe the qualities of Chlorine

Answer 29

Fairly reactive, poisonous dense green gas

Question 30

Describe the qualities of Bromine

Answer 30

Dense, poisonous, red-brown volatile liquid

Question 31

Describe the qualities of Iodine

Answer 31

A dark grey crystalline solid or a purple vapour

Question 32

Halogens all exist as molecules which are…

Answer 32

Pairs of atoms, they travel in twos