CHE 111 INTRODUCTION TO CHEMISTRY
1. The smallest unit of matter that retains the properties of an element is:
a) Atom
b) Molecule
c) Ion
d) Compound
2. Which subatomic particle has a negative charge?
a) Proton
b) Neutron
c) Electron
d) Nucleus
3. The atomic number of an element represents the number of:
a) Protons
b) Neutrons
c) Electrons
d) Nucleons
4. Isotopes of an element differ in their number of:
a) Protons
b) Electrons
c) Neutrons
d) Valence electrons
5. Which group on the periodic table contains noble gases?
a) Group 1
b) Group 2
c) Group 17
d) Group 18
6. The bond formed by the sharing of electrons is called:
a) Ionic bond
b) Covalent bond
c) Metallic bond
d) Hydrogen bond
7. Which state of matter has a definite volume but no definite shape?
a) Solid
b) Liquid
c) Gas
d) Plasma
8. In a chemical equation, the substances on the left side of the arrow are called:
a) Products
b) Reactants
c) Catalysts
d) Solvents
9. The molar mass of water (H₂O) is approximately:
a) 18 g/mol
b) 22 g/mol
c) 32 g/mol
d) 44 g/mol
10. A solution with a pH of 3 is classified as:
a) Acidic
b) Basic
c) Neutral
d) Alkaline
11. Which element is a liquid at room temperature?
a) Iron
b) Mercury
c) Sodium
d) Carbon
12. The process of a solid changing directly to a gas is called:
a) Melting
b) Sublimation
c) Condensation
d) Evaporation
13. Avogadro’s number is:
a) \(6.022 \times 10^{23}\)
b) \(3.0 \times 10^8\)
c) \(1.602 \times 10^{-19}\)
d) \(9.81\)
14. Which of the following is a chemical change?
a) Ice melting
b) Paper burning
c) Salt dissolving
d) Glass breaking
15. The formula for sodium chloride is:
a) NaCl
b) KCl
c) CaCO₃
d) H₂O
16. The SI unit for temperature is:
a) Fahrenheit
b) Celsius
c) Kelvin
d) Joule
17. Which gas is produced when metals react with acids?
a) Oxygen
b) Carbon dioxide
c) Hydrogen
d) Nitrogen
18. The Law of Conservation of Mass states that:
a) Mass cannot be created or destroyed
b) Energy is proportional to frequency
c) Pressure and volume are inversely related
d) Atoms are indivisible
19. Which of the following is a non-metal?
a) Sodium
b) Chlorine
c) Iron
d) Calcium
20. A catalyst speeds up a reaction by:
a) Increasing temperature
b) Lowering activation energy
c) Adding more reactants
d) Absorbing heat
21. The vertical columns in the periodic table are called _______.
22. The symbol for the element Gold is _______.
2 3. The process of separating liquids based on boiling points is called _______.
24. The formula for calculating density is _______.
25. The outermost electrons of an atom are called _______.
26. The number of moles in 36 grams of water (H₂O) is _______.
27. The chemical name for table salt is _______.
28. The pH of pure water at 25°C is _______.
29. A substance that cannot be broken down into simpler substances is called a(n) _______.
30. The bond between sodium (Na) and chlorine (Cl) in NaCl is _______.
31. Neutrons are positively charged.
True or false
32. All metals are solid at room temperature.
True or false
33. CO₂ is an example of a covalent compound.
True or false
34. The nucleus of an atom contains protons and electrons.
True or false
35. A solution with a pH of 12 is acidic.
True or false
36. The periodic table is arranged by increasing atomic number.
True or false
37. Evaporation occurs only at boiling point.
True or false
38. Oxygen is the most abundant gas in Earth’s atmosphere.
True or false
39. The molar mass of carbon is 12 g/mol.
True or false
40. Combustion reactions always produce water and CO₂.
True or false
.jpeg)
.jpeg)
0 Comments