jhg

2. Directions: Match column A with those in column B.
Column A Column B
1. Aristotle a) Discovered protons
2. Democritus b) Discovered neutrons
3.Ernest Rutherford c) Discovered electron
4. James Chadwick d) Laid the foundation of the atomic theory
5. John Dalton e) Established the existence of the nucleus of an
atom
6. Joseph Thomson f) Proposed that the atom is the smallest particle of
matter

3. B) Directions: Indicate the number of the three
subatomic particles of the following elements.
7.
𝟒𝟓
𝟐𝟏
𝑺𝒄 protons= _________ ; electrons= _________ ; neutron = _________
8.
𝟑𝟐
𝟏𝟔
𝑺 protons= _________ ; electrons= _________ ; neutron = _________
9.
𝟐𝟒𝟏
𝟗𝟓
𝑨𝒎 protons= _________ ; electrons= _________ ; neutron = _________
10.
𝟏
𝟏
𝑯 neutron = _________

4. Directions: Indicate the mass number, atomic number, number of protons (p+), number
of electrons (e-), number of neutrons (n0) of the following atoms.
Element nuclide Mass
number
Atomic
number
Subatomic Particles
Protons Electrons Neutrons
𝟏𝟏
𝟓
𝑩 11 5 5 5 6
𝟑𝟗
𝟏𝟗
𝑲 19 20
Argon -- Ar 40 22
--Fe 56 26
--S 16 16
𝟒𝟕
𝑨𝒈 108

5. Directions: Fill out the table.
Symbol Number of
Protons
Number of
Electrons
Number of
Neutron
Name of
Element
𝟒𝟓
𝟐𝟏
𝑺𝒄
𝟑𝟐
𝟏𝟔
𝑺
8
31 39