WorksheetsSCIENCE 8 2Q REVIEW
Total questions: 45
Worksheet time: 23mins
Who is credited with the idea that matter is made up of indivisible particles called “atomos”?
Aristotle
John Dalton
Democritus
J.J. Thomson
Which scientist discovered the electron using the cathode ray experiment?
Rutherford
Thomson
Bohr
Chadwick
According to Dalton’s atomic theory, which is TRUE?
Atoms can be divided into smaller particles.
Atoms of the same element are identical.
Atoms are mostly empty space.
Atoms contain protons and neutrons.
Which model described electrons orbiting the nucleus in fixed energy levels?
Dalton’s model
Rutherford’s model
Bohr’s model
Quantum mechanical model
Who discovered the neutron?
Thomson
Rutherford
Bohr
Chadwick
In Rutherford’s gold foil experiment, what observation led to the conclusion that the atom is mostly empty space?
Electrons were deflected.
Alpha particles bounced back.
Most alpha particles passed through.
Electrons orbited the nucleus.
The nucleus of an atom contains:
Protons and electrons
Protons and neutrons
Neutrons and electrons
Only protons
What is the charge of a neutron?
Positive
Negative
Neutral
Variable
Which particle determines the identity of an element?
Proton
Neutron
Electron
Nucleus
Which of the following represents the correct structure of an atom?
Electrons inside the nucleus
Protons outside the nucleus
Nucleus at the center, electrons around it
Electrons and protons together in the nucleus
What is the charge of an electron?
Positive
Negative
Neutral
Double positive
The mass of a proton is approximately equal to the mass of:
An electron
A neutron
A nucleus
Energy
Which subatomic particle is responsible for bonding?
Proton
Neutron
Electron
Nucleus
Where are electrons located?
In the nucleus
In energy levels around the nucleus
Between protons and neutrons
Alongside neutrons
Which particle has the smallest mass?
Proton
Neutron
Electron
Nucleus
Which correctly matches symbol, charge, and location?
Proton – negative – nucleus
Neutron – neutral – outside nucleus
Electron – negative – outside nucleus
Proton – positive – electron shell
Which of the following is a pure substance?
Air
Salt
Sugar solution
Milk
Elements and compounds are classified as:
Mixtures
Solutions
Pure substances
Colloids
Which statement is TRUE about elements?
They can be broken down into simpler substances.
All atoms of an element have the same number of protons.
They are formed by combining different compounds.
They do not have fixed composition.
Which is a compound?
Oxygen gas
Iron
Sodium chloride
Gold
Why is water considered a pure substance?
It can be separated physically.
It has a fixed chemical composition.
It has variable composition.
It is a mixture of hydrogen and oxygen.
Which is a type of pure substance which contains only one type of atom?
Compound
element
molecule
atom
Who is considered the father of the periodic table?
Newlands
Dalton
Mendeleev
Moseley
Mendeleev arranged the elements according to:
Atomic number
Atomic mass
Chemical symbol
Electron configuration
Moseley improved the periodic table by arranging elements based on:
Atomic weight
Atomic number
Valence electrons
Group properties
What law on the arrangement of the periodic table shows like a pattern on musical octaves?
Law of Triad
Law of Octave
Periodic law
law of Definite proportion
This arrangement on the periodic table groups elements into three with similar chemical properties where the atomic weight of the middle element is approximately the average of the other two.
Law of Triad
Law of Octave
Periodic law
law of Definite proportion
In the Mendeleev periodic table, vertical columns in the periodic table were named _______________.
Groups
Periods
Columns
Rows
What is the symbol of Sodium?
So
Sa
Na
S
Which of the following is NOT among the first 20 elements?
Calcium
Oxygen
Iron
Neon
The symbol “K” represents which element?
Krypton
Potassium
Kalium
Phosphorus
Which element has the symbol “Mg”?
Magnesium
Manganese
Mercury
Molybdenum
What is the average atomic mass of chlorine using its isotopes: Cl-35 (75%) and Cl-37 (25%)? Show your solution.
35.1
35.2
35.3
35.5
The periodic table has how many groups?
7
8
18
20
Which best explains why elements in the same group have similar properties?
Same number of protons
Same number of neutrons
Same number of valence electrons
Same atomic mass
Periods in the periodic table represent:
Number of neutrons
Number of electron shells
Number of protons
Atomic mass
Which group of elements is least reactive?
Alkali metals
Halogens
Noble gases
Transition metals
Which is a property of elements in Group 1?
Very stable
Inert gases
Highly reactive metals
Nonmetals
The vertical columns in the periodic table are called _______________.
Periods
Blocks
Levels
Groups
An element has an atomic number of 13 and mass number of 27. How many protons does it have?
13
14
27
40
Using the same element, how many neutrons does it have?
13
14
27
40
If an atom has 11 protons, how many electrons does it have?
10
11
12
22
Carbon-14 has how many neutrons? (Atomic number = 6)
6
8
14
20
Which is the correct number of protons, neutrons, and electrons in Oxygen-16?
8 p, 8 n, 8 e
8 p, 16 n, 8 e
16 p, 8 n, 16 e
8 p, 16 n, 16 e
An atom of sodium ( ²³₁₁Na ) has an atomic number of 11 and a mass number of 23. How many neutrons are in a sodium atom?
11
12
23
34
