Topic 2: Atomic Structure and the Periodic Table

Question 1

structure of an atom in terms of electrons, protons and neutrons

Answer 1

Atoms are mostly made up of empty space around a very small, dense nucleus that contains protons and neutrons
The nucleus has an overall positive charge
The protons have a positive charge and the neutrons have a neutral charge
Negatively charged electrons are found in orbitals in the empty space around the nucleus

Question 2

Atom

Answer 2

Atoms= which are the smallest parts of an element that can take place in chemical reactions.

Question 3

Subatomic particles

Answer 3

the particles an element is made up of and include protons, neutrons and electrons

Question 4

why is not possible to measure subatomic particles masses and charges using conventional ?

Answer 4

they are very small

Question 5

how do we measure subatomic particles masses and charge?

Answer 5

their masses and charges are compared to each other using ‘relative atomic masses’ and ‘relative atomic charges’
These are not actual charges and masses but they are charges and masses of particles relative to each other

Question 6

relative mass and charge of protons, neutrons and electrons?

Answer 6

Protons and neutrons have a very similar mass so each is assigned a relative mass of 1 whereas electrons are 1836 times smaller than a proton and neutron
Protons are positively charged, electrons negatively charged and neutrons are neutral

Question 7

atomic number (symbol Z )?

Answer 7

the number of protons in the nucleus of an atom
* atomic number = proton number = electron number

Question 8

mass number(nucleon number) (symbol A) =

Answer 8

the total number of protons and neutrons in the nucleus of an atom
* Number of neutrons = mass number - atomic number

Question 9

isotopes?

Answer 9

are atoms of the same element that contain the same number of protons and electrons but a different number of neutrons

Question 10

Properties of Isotopes

Answer 10

similar chemical properties but different physical properties

Chemical properties
* Same chemical properties because they have same number of outer shell electron.
(Electrons take part in chemical reactions and therefore determine the chemistry of an atom)

Physical properties
* difference between isotopes is the number of neutrons so because of this their mass number , boiling point and melting point is very different.

Question 11

what is a mass spectrometer?

Answer 11

instrument used to determine the relative isotopic mass and the relative abundance of each isotope

Question 12

define Relative isotopic mass

Answer 12

the mass of an individual isotope relative to the mass of carbon-12

Question 13

Uses of mass spectrometer

Answer 13

• detecting illegal drug
• forensic science
• space exploration
• carbon-14 dating