The atomic number of an element is determined by the number of:
1.Electrons
2.Protons
3.Neutrons
4.Positrons
The elements in the same group of the periodic table have:
1.Different numbers of protons
2.Different numbers of neutrons
3.Similar chemical properties
4.The same atomic mass
The number of atoms in one molecule of oxygen (O2) is:
1.1
2.2
3.3
4.4
The pH scale measures the acidity or basicity of a substance. A pH value of 7 indicates:
1.Strong acidity
2.Neutral solution
3.Strong basicity
4.Weak acidity
The process of conversion of a solid directly into vapor without passing through the liquid state is called:
1.Sublimation
2.Evaporation
3.Condensation
4.Fusion
The smallest particle of an element that retains its chemical properties is called:
1.Compound
2.Molecule
3.Atom
4.Proton
What is the atomic number of carbon?
1.6
2.12
3.14
4.16
What is the chemical symbol for iron?
1.Ir
2.Fe
3.Io
4.In
What is the chemical symbol for iron?
1.Ir
2.Fe
3.Io
4.In
What is the chemical symbol for potassium?
1.P
2.K
3.Pt
4.Ka
What is the formula for sulfuric acid?
1.H2SO3
2.H2SO4
3.H2S
4.HSO4
What is the formula for the compound formed between calcium and chlorine?
1.CaCl
2.CaCl2
3.Ca2Cl
4.Ca2Cl2
What is the process of conversion of a gas into a liquid called?
1.Condensation
2.Evaporation
3.Sublimation
4.Solidification
Which gas is most abundant in the Earth's atmosphere?
1.Nitrogen
2.Oxygen
3.Carbon dioxide
4.Argon
Which gas is produced during photosynthesis?
1.Oxygen
2.Carbon dioxide
3.Hydrogen
4.Nitrogen
Which of the following is NOT a greenhouse gas?
1.Compound
2.Molecule
3.Atom
4.Proton
Which of the following is NOT a greenhouse gas?
1. Carbon dioxide
2.Methane
3.Nitrogen
4.Water vapor
Which of these elements is a noble gas?
1.Hydrogen
2.Helium
3.Sodium
4.Oxygen