929-Mass Numbers inc Isotopes Presentation.ppt

The power point deals with isotopes, definition and examples. It deals with the explanation of physical and chemical properties of isotopes and reasons behind it. The isotopes of hydrogen, chlorine are discussed. It also deals with the uses of various isotopes. Industrial and medicinal uses of various isotopes. How chemical properties are determined. why isotopes have same chemical properties but different physical properties.

1. Write concise
definitions for these
words
protonelectron
neutronshells

2. Atomic Structure –Inside the Atom
Dalton described the atoms as particles that cannot be
split. However the atom is made of smaller sub-atomic
particles
e.g.
An atom of
lithium

3. Atomic Structure –Inside the Atom
There are three types of particle inside the atom –
protons, neutronsand electrons
Protons
Neutrons
Electrons
An atom of
lithium

4. Atomic Structure –Inside the Atom
The sub-atomic particles have different charges and
masses
ParticleCharge Mass
(in atomic
units)
Proton 1+ 1
Neutron 0 1
Electron 1- 0

5. Atomic Structure –Inside the Atom
Each element has its own atomic number, it tells us how
many protons there are in one atom of that element.
Atomic number = number of protons
Atoms are neutral (they have no charge). So the number of
electrons equals the number of protons.

6. Atomic Structure –Inside the Atom
Mass number tells us how many protons and neutrons there
are in an atom..remember electrons are so small we
approximate their mass to zero
Mass number = number of protons + number of neutrons

7. Isotopes
Atoms of the same element always have the same number of
protons. However they may have different numbers of
neutrons. There are known as isotopes. Carbon has two
isotopes:
C C
6
14
6
12
Write down the number of protons, neutrons and electrons
in the two isotopes of carbon
Carbon-12 Carbon-14

8. Different isotopes of the same element may have different
physical propertiese.g. melting point or density. Some
isotopes are radioactive
However they always have the same chemical properties.
A good example is hydrogen…

9. Hydrogen exists as 3 isotopes…
although Hydrogen-1 makes up the vast
majority of the naturally occurring element.
H
1
1 H
2
1 H
3
1
Protons
Electrons
Neutrons
Hydrogen
Protons
Electrons
Neutrons
(Deuterium)
Protons
Electrons
Neutrons
(Tritium)
All have a different mass, tritium is radioactive but
all react with oxygen to form water

10. 1.Which of the following is not a sub-
atomic particle?
A.Proton.
B.Isotope.
C.Neutron.
D.Electron.

11. 2.The element Cobalt has a relative atomic
mass of 59 and an atomic number of 27.
Which of these is a true statement about
each neutral cobalt atom?
A.It contains 59 neutrons.
B.It contains 27 electrons.
C.It contains 32 protons.
D.It contains equal numbers of neutrons and
electrons.

12. 3.The Periodic Table displays iron as shown
below. This indicates that Fe atoms:
A.contain 56 neutrons.
B.contain 30 electrons.
C.contain 26 protons.
D.contains more protons than neutrons.
56
Fe
26

13. 4.Bromine consists of a mixture of two
isotopes: Bromine-79 and Bromine-81
•Which of the following is true:
A.Both isotopes contain 35 protons.
B.Bromine 79 contains 46 neutrons.
C.Bromine 81 contains 44 neutrons.
D.Bromine-81 is more reactive than bromine-
79.
80
Br
35

14. 5.Natural boron consists of approx. 20%
boron-10 and 80% boron-11.
•What will the relative atomic mass of natural
boron will be?
A.10.0
B.11.0
C.10.5
D.10.8
?
B
5

15. 6.Which answer best describes the shell
arrangement of the electrons in a sodium
atom?
A.2,8,1.
B.2,2,7.
C.2,8,8,3.
D.2,8,8,1.
23
Na
11

16. 7.Which answer best describes the shell
arrangement of the electrons in an
oxygen atom?
A.2,8,6.
B.2,8,8.
C.2,8.
D.2,6.
16
O
8

17. 8.Which of these elements will have
electron shells that are either full or
empty (i.e. not partially full)?
14
N
7
A
40
Ar
18
B
40
Ca
20
C 27
Al
13
D

18. 9.Which answer best describes the shell
arrangement of the electrons in an
oxide ion O
2-
?
A.2,8,6.
B.2,8.
C.2,8,8.
D.2,6.
16
O
8