YEAR 9 – Topic 3 – Atomic Structure

Question 1

What is an atom?

Answer 1

The simplest particle of an element.

Question 2

What is a molecule?

Answer 2

A molecule is a 2 or more of some atoms chemically bonded together.

Question 3

What is the structure of an atom?

Where are the sub-atomic particles?

Answer 3

Electrons –> orbitals

Protons + neutrons –> neucleus

Question 4

What is the relative mass of an atom and how can we work this out?

Answer 4

–The relative mass of an atom is the number of protons and neutrons.
–To find it out, look at the mass number on the element symbol.
–To work it out, add the protons and neutrons

Question 5

What is the atomic number?

Answer 5

– The number to the bottom left of the symbol.

– This is the number of protons.

Question 6

What is the mass number?

Answer 6

– The number to the top left of the symbol.
– The number of protons + neutrons
(MASSive number)

Question 7

What are isotopes?

Answer 7

–Isotopes are atoms with the same number of protons and electrons, but a different number of neutrons.
–This means that the atomic number stays the same, but the relative mass number changes.
–It can get bigger and smaller.

Question 8

What is Ar?

Answer 8

Relative atomic mass.

Question 9

How do we calculate the relative atomic mass of an element (Ar) from isotopic abundances?

Answer 9

– You take the “amount” of atoms with that isotope and put it into a percentage…
- eg. 35/17 Cl is 75.8% and 37/17 Cl is 24.2%
– That way you have the abundance of the atom.
– Then you use the relative atomic mass and times it by the abundance of one isotope and add it to the relative atomic mass times by the abundance of the other isotopes.
– You then divide it by the total abundance which should be 100%. You now have the (average) relative atomic mass (Ar)!!!!!!

Basically: (abundance x Ar) + (abundance x Ar) (etc)
. ––––––––––––––––––––––––––––––
. 100

Do some Qs on this and if you don’t understand we did it under the title of isotopes and electronics configuration.

Question 10

What is the relative charge of a proton?

Answer 10

+1

Question 11

What is the relative charge of a neutron?

Answer 11

0

Question 12

What is the relative charge of a electron?

Answer 12

-1

Question 13

What is the relative mass of a proton?

Answer 13

1

Question 14

What is the relative mass of a neutron?

Answer 14

1

Question 15

What is the relative mass of a electron?

Answer 15

. 1
.——
1840

(Or just 0!!!)

Question 16

Where is a proton located?

Answer 16

In the nucleus.

Question 17

Where is a neutron located?

Answer 17

In the nucleus.

Question 18

Where is a electron located?

Answer 18

In the orbitals.

Question 19

Can atoms have electric charge?

Answer 19

No. Only ions can.

Question 20

What is a sub-atomic particle?

Answer 20

A proton, neutron or electron.

Question 21

The atomic number is…

Answer 21

The number of protons (which in non ions, is also the number of electrons)

Question 22

The mass number is…

Answer 22

The number of protons and neutrons.

Question 23

True or false…

Atoms will always have the same number of protons and electrons.

Answer 23

True! Atoms technically are not ions so they do!

Be careful with that though as ions have different amounts of electrons to atoms, indicated by the pluses and minuses to the upper right of the element.

Question 24

What does the amount of neutrons tell us about an atom?

Answer 24

Whether it is an isotope or not.

Question 25

What does the amount of protons tell us about an atom?

Answer 25

What element it is.

Question 26

What does the amount of electrons tell us about an atom?

Answer 26

Whether is is an ion or not.

Question 27

What is an ion?

Answer 27

An ion is a charged particle. This means that is has lost or gained up to 4 electrons.
I think…..

Question 28

How many electrons are in the first shell?

Answer 28

2

Question 29

How many electrons are in the second shell?

Answer 29

8

Question 30

How many electrons are in the third shell?

Answer 30

8