Domestic electrical wiring is basically a ______.

combination of series and parallel connections

series connection within each room and parallel connection elsewhere

The conversion of kinetic energy to potential energy is best illustrated by:

A ball thrown upward slowing down as it rises

A generator producing electricity

A ball thrown upward slowing down as it rises

Which of the following statements describes Newton’s Third Law of Motion?

For every action, there is an equal and opposite reaction.

The volume of a given mass of gas increases or decreases with temperature.

For every action, there is an equal and opposite reaction.

At a constant temperature, the volume of a given mass of gas varies inversely with pressure.

There is an attraction or repulsion between two electric charges.

In the modern periodic table what runs horizontally and shows how many electron shells are occupied in the neutral atom in its ground state for the lightest member of that row?

A period shows how many shells are filled up to the outermost shell for the first element in that row

A group shows occupied shells for the lightest atom in that column

A period shows how many shells are filled up to the outermost shell for the first element in that row

A block shows how many shells exist for every element listed in that block

A family always equals the number of shells for the heaviest element in that column

Sodium catches fire in water with a yellow flame while argon sits in light bulbs without reacting. Which periodic pattern best explains this everyday contrast?

Argon has a full valence shell so it resists ordinary bonding while sodium readily loses an electron

Argon is lighter than sodium so it floats above reactions

Sodium is a nonmetal so it cannot ignite in water

Noble gases are always liquids at room temperature so they stop reactions

Newlands proposed an early octave pattern and Mendeleev left gaps for undiscovered elements. What did Moseley’s work later make the reliable organizing number for the long-form table?

Density in grams per cubic centimetre only

Compared with lithium in the same group why does potassium often react more violently with cold water in classroom demos?

Potassium has more electron shells so its outer electron is farther from the nucleus and easier to remove

Potassium has fewer electron shells so its nucleus pulls harder on all electrons equally

Potassium is a transition metal so it cannot lose electrons easily

Potassium is in Period 2 so it should be less reactive than lithium

Across Period 3 from sodium to chlorine what is the general trend in atomic radius for isolated neutral atoms?

It decreases overall because the rising nuclear charge pulls the same-shell electrons closer

It increases steadily because each step adds a new electron shell

It decreases overall because the rising nuclear charge pulls the same-shell electrons closer

It stays exactly the same because all are in Period 3

It increases only for metals then drops to zero for nonmetals

Moving down Group 17 from fluorine to iodine what happens to the atomic radius of the neutral atoms?

Radius increases because new electron shells are added down the group

Radius decreases because halogens become less metallic down the group

Radius increases because new electron shells are added down the group

Radius stays constant because halogens always have seven valence electrons

Radius decreases because nuclear charge decreases down the group

First ionization energy is the energy needed to remove one electron from a neutral gaseous atom. What is the usual trend across a period from left to right?

It generally increases because effective nuclear attraction to valence electrons rises

It generally decreases because atoms get bigger across a period

It is highest for alkali metals on the left

It is identical for all elements in the same period

In many introductory schemes the Roman numeral A group number for main-group elements equals what simple electron count for the atom?

The number of valence electrons for representative groups in basic rules

The total number of electrons in all shells combined

The number of neutrons in the nucleus

The number of valence electrons for representative groups in basic rules

The number of core electrons only

Hydrogen is tricky on a wall chart. Which statement matches how hydrogen is usually classified in broad introductory periodic discussions?

Hydrogen is a nonmetal placed above Group 1 but it is not a typical alkali metal in behaviour

Hydrogen is always grouped with the halogens because it always forms H+ in every compound

Hydrogen is a transition metal because it can lose electrons

Hydrogen is a noble gas because it is the smallest atom

Punjab Revenue Authority (PRA) Assistant / Inspector Everyday Science Periodic Table MCQs with Answers

Punjab Revenue Authority (PRA) Assistant / Inspector Everyday Science: Periodic Table MCQs — sample questions

Question 1
Q1. What is the atomic number of carbon?
- A) 6
- B) 8
- C) 12
- D) 4
Answer: 6
Explanation: Carbon has atomic number 6, meaning it has 6 protons in its nucleus; its atomic mass is approximately 12 u.
Question 2
Q2. What is the chemical symbol for gold?
- A) Au
- B) Go
- C) Gd
- D) Ag
Answer: Au
Explanation: Gold's chemical symbol is Au, derived from the Latin word "Aurum." Its atomic number is 79 on the periodic table.
Question 3
Q3. Which element has the highest atomic number on the standard periodic table?
- A) Uranium (U)
- B) Oganesson (Og)
- C) Plutonium (Pu)
- D) Radium (Ra)
Answer: Oganesson (Og)
Explanation: Oganesson (Og) has atomic number 118 and is currently the last element on the periodic table; uranium (92) and plutonium (94) are much lower.
Question 4
Q4. What is the lightest element on the periodic table?
- A) Helium
- B) Hydrogen
- C) Lithium
- D) Carbon
Answer: Hydrogen
Explanation: Hydrogen (H) is the lightest and most abundant element in the universe, with atomic number 1 and atomic mass approximately 1 u.
Question 5
Q5. The chemical symbol for iron is:
- A) Ir
- B) Fe
- C) In
- D) Fr
Answer: Fe
Explanation: Iron's symbol Fe comes from the Latin "Ferrum"; iron has atomic number 26 and is essential in steel production and biological processes.
Question 6
Q6. How many elements are currently in the periodic table?
- A) 92
- B) 108
- C) 118
- D) 126
Answer: 118
Explanation: The modern periodic table contains 118 confirmed elements, from hydrogen (1) to oganesson (118), as recognized by IUPAC.
Question 7
Q7. What is the atomic number of oxygen?
- A) 6
- B) 16
- C) 8
- D) 10
Answer: 8
Explanation: Oxygen has atomic number 8, meaning it has 8 protons in its nucleus; its atomic mass is approximately 16 u and its electron configuration is 2,6.
Question 8
Q8. The atomic number of gold (Au) is:
- A) 47
- B) 29
- C) 92
- D) 79
Answer: 79
Explanation: Gold (Au) has atomic number 79, meaning 79 protons in its nucleus; silver (Ag) has 47 and copper (Cu) has 29.
Question 9
Q9. Which of the following correctly lists elements in order of increasing atomic number?
- A) Carbon, Oxygen, Hydrogen, Iron
- B) Iron, Carbon, Oxygen, Hydrogen
- C) Oxygen, Carbon, Iron, Hydrogen
- D) Hydrogen, Carbon, Oxygen, Iron
Answer: Hydrogen, Carbon, Oxygen, Iron
Explanation: H=1, C=6, O=8, Fe=26 - so the correct ascending order of atomic number is Hydrogen (1), Carbon (6), Oxygen (8), Iron (26).
Question 10
Q10. In the modern periodic table what runs horizontally and shows how many electron shells are occupied in the neutral atom in its ground state for the lightest member of that row?
- A) A group shows occupied shells for the lightest atom in that column
- B) A period shows how many shells are filled up to the outermost shell for the first element in that row
- C) A block shows how many shells exist for every element listed in that block
- D) A family always equals the number of shells for the heaviest element in that column
Answer: A period shows how many shells are filled up to the outermost shell for the first element in that row
Explanation: In the periodic table, periods run horizontally; elements in the same period have the same number of electron shells, with the period number indicating the highest occupied principal quantum number.
Question 11
Q11. Which group is best described as highly reactive nonmetals that often form salts with alkali metals and are missing one valence electron to reach a noble gas configuration in many simple textbook cases?
- A) Group 2 alkaline earth metals
- B) Group 17 halogens
- C) Group 18 noble gases
- D) Group 11 coinage metals
Answer: Group 17 halogens
Explanation: Group 17 halogens have seven valence electrons, making them one electron short of a noble gas configuration; this drives their high reactivity and tendency to form salts (e.g., NaCl) with alkali metals.
Question 12
Q12. Sodium catches fire in water with a yellow flame while argon sits in light bulbs without reacting. Which periodic pattern best explains this everyday contrast?
- A) Argon has a full valence shell so it resists ordinary bonding while sodium readily loses an electron
- B) Argon is lighter than sodium so it floats above reactions
- C) Sodium is a nonmetal so it cannot ignite in water
- D) Noble gases are always liquids at room temperature so they stop reactions
Answer: Argon has a full valence shell so it resists ordinary bonding while sodium readily loses an electron
Explanation: Argon has a complete outermost electron shell (eight valence electrons), giving it no tendency to gain or lose electrons; sodium has one valence electron it readily donates, making it highly reactive with water.
Question 13
Q13. Newlands proposed an early octave pattern and Mendeleev left gaps for undiscovered elements. What did Moseley’s work later make the reliable organizing number for the long-form table?
- A) Atomic mass only
- B) Neutron count only
- C) Atomic number
- D) Density in grams per cubic centimetre only
Answer: Atomic number
Explanation: Henry Moseley showed in 1913 that bombarding elements with X-rays revealed a unique atomic number (proton count) for each element; arranging elements by atomic number resolved anomalies in Mendeleev's mass-based table and became the reliable organising principle of the modern periodic table.
Question 14
Q14. Compared with lithium in the same group why does potassium often react more violently with cold water in classroom demos?
- A) Potassium has more electron shells so its outer electron is farther from the nucleus and easier to remove
- B) Potassium has fewer electron shells so its nucleus pulls harder on all electrons equally
- C) Potassium is a transition metal so it cannot lose electrons easily
- D) Potassium is in Period 2 so it should be less reactive than lithium
Answer: Potassium has more electron shells so its outer electron is farther from the nucleus and easier to remove
Explanation: Potassium (K) is in Period 4, giving it more electron shells than lithium (Li) in Period 2, which places the outermost valence electron much farther from the nucleus and more shielded from its attractive pull, making it easier to remove.
Question 15
Q15. Across Period 3 from sodium to chlorine what is the general trend in atomic radius for isolated neutral atoms?
- A) It increases steadily because each step adds a new electron shell
- B) It decreases overall because the rising nuclear charge pulls the same-shell electrons closer
- C) It stays exactly the same because all are in Period 3
- D) It increases only for metals then drops to zero for nonmetals
Answer: It decreases overall because the rising nuclear charge pulls the same-shell electrons closer
Explanation: Across Period 3, nuclear charge increases from +11 (Na) to +17 (Cl) while electrons are added to the same third shell; the stronger nuclear pull draws the electron cloud inward, steadily decreasing atomic radius.
Question 16
Q16. Moving down Group 17 from fluorine to iodine what happens to the atomic radius of the neutral atoms?
- A) Radius decreases because halogens become less metallic down the group
- B) Radius increases because new electron shells are added down the group
- C) Radius stays constant because halogens always have seven valence electrons
- D) Radius decreases because nuclear charge decreases down the group
Answer: Radius increases because new electron shells are added down the group
Explanation: Moving down Group 17, each successive element gains an additional electron shell, increasing the distance from the nucleus to the outermost electrons and therefore increasing atomic radius.
Question 17
Q17. First ionization energy is the energy needed to remove one electron from a neutral gaseous atom. What is the usual trend across a period from left to right?
- A) It generally increases because effective nuclear attraction to valence electrons rises
- B) It generally decreases because atoms get bigger across a period
- C) It is highest for alkali metals on the left
- D) It is identical for all elements in the same period
Answer: It generally increases because effective nuclear attraction to valence electrons rises
Explanation: Across a period, the nuclear charge increases while electrons are added to the same shell, increasing effective nuclear charge and pulling valence electrons closer, so more energy is needed to remove them.
Question 18
Q18. Which family is labeled Group 2 and is known for forming +2 ions and giving characteristic flame colours in some simple chemistry demos?
- A) Alkali metals
- B) Alkaline earth metals
- C) Halogens
- D) Noble gases
Answer: Alkaline earth metals
Explanation: Group 2 elements - beryllium, magnesium, calcium, strontium, barium, and radium - are called the alkaline earth metals because they form alkaline (basic) oxides and hydroxides, and many occur naturally in the earth as minerals.
Question 19
Q19. In many introductory schemes the Roman numeral A group number for main-group elements equals what simple electron count for the atom?
- A) The total number of electrons in all shells combined
- B) The number of neutrons in the nucleus
- C) The number of valence electrons for representative groups in basic rules
- D) The number of core electrons only
Answer: The number of valence electrons for representative groups in basic rules
Explanation: In the traditional Roman-numeral A-group system, the group number directly equals the number of valence (outermost shell) electrons for representative main-group elements, which determines their typical combining capacity.
Question 20
Q20. Hydrogen is tricky on a wall chart. Which statement matches how hydrogen is usually classified in broad introductory periodic discussions?
- A) Hydrogen is a nonmetal placed above Group 1 but it is not a typical alkali metal in behaviour
- B) Hydrogen is always grouped with the halogens because it always forms H+ in every compound
- C) Hydrogen is a transition metal because it can lose electrons
- D) Hydrogen is a noble gas because it is the smallest atom
Answer: Hydrogen is a nonmetal placed above Group 1 but it is not a typical alkali metal in behaviour
Explanation: Hydrogen is a nonmetal that is conventionally placed above Group 1 on the periodic table because it has one valence electron, yet it does not share the typical alkali-metal properties such as being a soft, lustrous, reactive solid at room temperature.