these are the specification points you need to understand

These are the specification points you need to understand from this work

Work through the slides and copy out information into your chemistry book when

asked to.

Any problems:e.shore@bishopchalloner,bham.sch.uk

mailto:e.shore@bishopchalloner,bham.sch.uk

Starter

• To begin with, let us see how much you remember from last week’s lesson.

You will need to use this from last lesson:

4 of 19 © Boardworks Ltd 2011

Atomic structure revision


Answers

Isotopes

Objectives:

• To know how to work out the numbers of protons, neutrons and electrons in an atom.

• To understand what isotopes are.

• To be able to work out the number of p,n and electrons in different isotopes.

• To be able to answer question.


What is an isotope?

Atoms of an element can come in slightly different forms.

mass number

is different

atomic number

is the same

Atoms that differ in this way are called isotopes.

What do atoms of the same element always have the same

number of?

protons

For example, two isotopes of carbon:

Copy into your book


mass number

is different

atomic number

is the same

These two isotopes are called:

carbon-12 and carbon-13. The number written is the

mass number.


This is not a minus sign, it is a hyphen

Copy the purple writing into your book


What is an isotope?

mass number

is different

atomic number

is the same

What is different about the two isotopes, the number of

protons, neutrons or electrons ?



mass number

is different

atomic number

is the same

Protons: the atomic number is the same for both, this means

the number of protons is the same.

Electrons:remember that in an atom, the number of electrons is

the same as the number of protons, so the number of electrons

is the same for both.

Neutrons: mass number = protons + neutrons.

The mass number is different for the two isotopes and as the

number of protons stays the same, it must be the number of

neutrons that is different.For example, two isotopes of carbon:

Copy the purple writing into your book


What is an isotope?

mass number

is different

atomic number

is the same

Definition

Isotopes are atoms of the same element with the same

number of protons and electrons but a different

number of neutrons.


Copy the purple writing into your book.

You need to learn this definition.


• If you have internet access, watch the

following Bitesize video:

• https://www.bbc.co.uk/bitesize/clips/z89n3

4j

https://www.bbc.co.uk/bitesize/clips/z89n34j


The isotopes of an element are virtually identical in their

chemical reactions.

The uncharged neutrons make little difference to chemical

properties, but do affect physical properties such as melting

point and density.

Natural samples of elements are often a mixture of isotopes.

This is because they

all have the same

number of protons

and the same

number of electrons.

Copy into your book

Isotopes

Objectives:




• To be able to answer question.


How many protons, neutrons and electrons are

present in different isotopes?

Most naturally-occurring carbon exists as carbon-12, about

1% is carbon-13 and a much smaller amount is carbon-14.

6 protons

6 electrons

6 neutrons

6 protons

6 electrons

7 neutrons

6 protons

6 electrons

8 neutrons


Hydrogen-1 makes up the vast majority of the naturally-

occurring element, but two other isotopes exist.

1 proton

0 neutrons

1 electron

hydrogen

1 proton

1 neutron

1 electron

deuterium

1 proton

2 neutrons

1 electron

tritium

Can you work out how many protons, neutrons and electrons

are present in the below hydrogen isotopes?


What are the isotopes of hydrogen?

Hydrogen-1 makes up the vast majority of the naturally-

occurring element, but two other isotopes exist.

1 proton

0 neutrons

1 electron

hydrogen

1 proton

1 neutron

1 electron

deuterium

1 proton

2 neutrons

1 electron

tritium

Answers


What are the isotopes of chlorine?

About 75% of naturally-occurring chlorine is chlorine-35, and

25% is chlorine-37.

17 protons

18 neutrons

17 electrons

17 protons

20 neutrons

17 electrons


are present in the below chlorine isotopes?


What are the isotopes of chlorine?

About 75% of naturally-occurring chlorine is chlorine-35, and

25% is chlorine-37.

17 protons

18 neutrons

17 electrons

17 protons

20 neutrons

17 electrons

Answers


What are the particle numbers in each isotope below?

What are the isotopes of oxygen?

Almost all naturally-occurring oxygen is oxygen-16, but

about 0.2% is oxygen-18.

oxygen-16

8 protons

8 neutrons

8 electrons

oxygen-18

8 protons

10 neutrons

8 electrons


are present in the below oxygen isotopes?


What are the particle numbers in each isotope below?

What are the isotopes of oxygen?

Almost all naturally-occurring oxygen is oxygen-16, but

about 0.2% is oxygen-18.

oxygen-16

8 protons

8 neutrons

8 electrons

oxygen-18

8 protons

10 neutrons

8 electrons

Answers

Isotopes

Objectives:




• To be able to answer questions.


• You will need your periodic table for the

next questions.

Copy out and complete the below table

Answers

Copy out and complete the below table

Answers


Knowledge check

• Can you answer the following questions?

1. What are isotopes?

2. Which number is different for isotopes, atomic number or

mass number?

3. Why do isotopes of an element have the same chemical

property?

4. State a particular physical property that might be

different for two isotopes of an element?

1. What are isotopes?

Atoms of the same element with the same number of

protons and electrons but a different number of neutrons.

2. Which number is different for isotopes, atomic number or

mass number?

mass number

3. Why do isotopes of an element have the same chemical

property?

Because it is the electrons and protons of an element that

determine the chemical properties of an element and these

are the same in isotopes of an element.

4. State a particular physical property that might be

different for two isotopes of an element?

melting point or boiling point

Well done, that is the end of

week 6 chemistry.

these are the specification points you need to understand

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