2025/2026 1st Term Examination on Chemistry for JS1

1. Which state of matter has a definite shape and definite volume?

2. Particles in solids move by –

3. Which change of state occurs when a liquid becomes gas

4. Condensation is the process where

5. Dry ice changing directly into carbon dioxide basis an example of

6. Which process requires heat to be released

7. The process where gas changes directly into solid is called

8. Which of the following increases when matter absorbs heat?

9. During melting, the particles of a solid

10. Which of the following is the first step in the scientific method?

11. A testable statement made to explain an observation is called a

12. Which step of the scientific method involves collecting measurements and making tables or graphs?

13. A good scientific attitude requires that conclusions should be based on

14. Which step of the scientific method tests whether a hypothesis is correct

15. A scientist carefully checks results many times before accepting them. This shows

16. Which of the following is a major health effect of prolonged exposure to toxic chemicals?

17. The best way to prevent chemical accident in laboratories

18.A key preventive measure against chemical pollution in industries is;

19. Which career involves testing air, water and soil for pollutants?

20. Which of these is a societal adverse effect of chemistry?

21. The statements "matter is made up of tiny particles" refers to the;

22. Which sub-atomic particles has a negative charge?

23. The center of an atom is called the

24. Who proposed the first modern atomic theory?

25. A chemical reaction involves

26. The tiny particles of matter are always in –

27. The sub-atomic particle with a positive charge is the

28. Dalton stated that atoms of the same element are –

29. Which of these is NOT a sub-atomic particles

30. Matte exists in which 3 main states?

SECTION B (ANSWER ALL)

1. The total number of protons and neutrons in an atom is called –

2. The sub atomic particle found outside the nucleus is –

3. – is the branch of science that studies matter

4. The part of the atom where protons and neutrons are found is the –

5. – is the smallest particle of an element that takes part in a chemical reaction

6. Matter is anything that has –

7. The sub-atomic particle with no charge is the –

8. Sublimation is the process where – changes to – directly

9. When movement of particles of matter increases from solid to liquid to gas, heat is said to be –

10. When movement of particles of matter reduces from gas to liquid to solid, heat is said to be –

THEORY (ANSWER 4 QUESTIONS)

1a. What is science? 1b. Who is a scientist? 1c. Mention 3 scientific attitude or qualities

2a. Define chemistry 2b. Mention two careers in chemistry 2c. State two adverse effects of chemistry.

3a. What is scientific method 3b. List the steps involved in scientific method

4a. What is meant by change of state of matter? 4b. Explain the following: I. Melting II. Freezing Iii. Evaporation or boiling Iv. Condensation

5a. Define an atom 5b. What is atomic number 5c. What is mass number

6. Potassium has 19 protons and 20 neutrons a. How many electrons does it have? b. Calculate the mass number of the element c. Draw the electronic configuration of the element.