Atomic structure

Question 1

how are atoms arranged in the periodic table

Answer 1

Elements are arranged in the periodic
table according to their atomic number,
represented by Z. It is defined as the number of protons in the atom.

Question 2

what is mass number

Answer 2

The mass number, given the symbol A, is defined as the number of protons
plus the number of neutrons in an atom

Question 3

what are isotopes

Answer 3

Atoms (of the same element) with same number of protons but different numbers of neutrons.

Question 4

chemical properties of isotopes

Answer 4

Isotopes have the same chemical properties - as chemical reactions depend on the number of electrons in the outermost shells.

Question 5

physical properties of isotopes

Answer 5

● Difference in atomic mass leads to different physical properties such as density, boiling point and melting point.

● Heavier isotopes move more slowly at a given temperature and therefore have
higher melting and boiling points.

Question 6

what is a mass spectrometer used for

Answer 6

mass spectrometer can be used,
showing the isotopic composition of an element on a mass spectrum.

Question 7

what is deflection based on in a mass spectrometer

Answer 7

Deflection based on
mass to charge ratio
(m/z) of ion:

More deflection on
● Lower mass
● Higher charge

Question 8

Cl2 molecules:
m/z = 70 due to

Answer 8

(35Cl - 35Cl)+

Question 9

Cl2 molecules
m/z = 72 due to

Answer 9

(35Cl - 37Cl)+

Question 10

Cl2 molecules
m/z = 74 due to

Answer 10

(37Cl - 37Cl)+

Question 11

what is relative atomic mass

Answer 11

● The weighted average mass of atoms of an element

● Relative to the mass of 1/12 of a Carbon-12 atom*

Question 12

what are chemical reactions

Answer 12

Chemical reactions are the processes that transforming one set of chemical substances to another one.

Question 13

what in involved in a chemical reaction

Answer 13

During reactions, only the outermost shell / valence electron(s) is/are involved.