C1 Atomic structure: Isotopes
Embedded Files
ISOTOPES are atoms of the same element,
with the same number of protons, but different number of neutrons.
See the example below:
Neon-20 and Neon-22 are isotopes because:
they are atoms of the same element, neon.
they have the same number of protons, which is 10 protons.
they have different number of neutrons, Neon-20 has 10 neutrons whereas Neon-22 has 12 neutrons.
ISOTOPES have the same atomic number, but different mass number.
Isotopes have the same chemical properties
because the atoms have the same number of electrons.
Isotopes have different physical properties,
such as different densities, melting points and boiling points,
because the atoms have different number of neutrons.
Sometimes the extra neutrons make the nucleus unstable, so it is radioactive.
Q1. What is the atomic number? (1)
number of protons
Q2. What is the mass number (atomic mass)? (1)
number of protons + number of neutrons
Q3. How do we work out the neutron number? (1)
number of neutrons = mass number - atomic number
Q4. Bromine has two different types of atoms. The atoms have a different number of neutrons but the same number of protons.
What is the name for these types of atoms?
isotopes
Q5. Give the meaning of ‘isotopes’. You should answer in terms of sub-atomic particles. (2)
Q5. Give the meaning of ‘isotopes’. You should answer in terms of sub-atomic particles. (2)
1. atoms with the same number of protons
2. but with different numbers of neutrons
Q6. Why is the mass number different in two isotopes? (1)
the isotopes contain different numbers of neutrons
Q7. Different atoms of argon are represented in the diagram below:
What is the name given to these different atoms of argon? (1)
isotopes
Q8. C – 12 and C – 14 are isotopes of carbon. The isotopes of carbon have the same number of _____________________. (1)
The isotopes of carbon have the same number of protons.
Q9. C – 12 and C – 14 are isotopes of carbon. The isotopes of carbon different number of _____________________. (1)
The isotopes of carbon have different number of neutrons.
Q10. Explain why C – 12 and C – 14 are isotopes of carbon. You should refer to the numbers of sub-atomic particles in the nucleus of each isotope. (3)
Both atoms have 6 protons in the nucleus, but different number of neutrons
C – 12 has 6 neutrons in the nucleus
C – 14 has 8 neutrons in the nucleus
Q11. There are two isotopes of the element chlorine:
Describe, in terms of sub-atomic particles, one similarity between atoms of the two isotopes of chlorine. (1)
same number (17) protons
or same number electrons
Q12. There are two isotopes of the element chlorine:
Describe, in terms of sub-atomic particles, one difference between atoms of the two isotopes of chlorine. (1)
different numbers of neutrons
35Cl has 18 neutrons
37Cl has 20 neutrons
Q13. There are two isotopes of the element oxygen:
Describe the similarities and differences between the isotopes.
You should refer to the numbers of sub-atomic particles in each isotope. (3)
Both atoms of oxygen have 8 protons
Oxygen – 18 has 10 neutrons
Oxygen – 16 has 8 neutrons
Q14. Gallium (Ga) is an element that has two isotopes.
Give the meaning of ‘isotopes’.
You should answer in terms of sub-atomic particles. (2)
atoms with the same number of protons
but with different numbers of neutrons
Q15. Three isotopes of hydrogen are hydrogen-1, hydrogen -2 and hydrogen-3.
The diagram below represents these hydrogen isotopes.
Explain what is meant by isotopes.
In your explanation, you must include the numbers of electrons, neutrons and protons in the atoms of hydrogen. (4)
isotopes are atoms of the same element
all hydrogen atoms have 1 proton / the same number of protons
all hydrogen atoms have 1 electron / the same number of electrons
all hydrogen atoms have different numbers of neutrons, hydrogen-1 has no neutrons, hydrogen-2 has 1 neutron and hydrogen-3 has 2 neutrons.
Page updated
Google Sites
Report abuse