Chemistry Class 11

What is the atomic number of carbon?

• 8

• 12

• 3

• 6

Define Avogadro's number.

• 2.718

• 9.81

• 3.1416

• 6.022 x 10^23

What is the difference between an element and a compound?

• An element is a substance made up of two or more different types of atoms chemically bonded together, while a compound is a pure substance made up of only one type of atom

• An element is a pure substance made up of only one type of atom, while a compound is a mixture of different types of atoms

• An element is a mixture of different types of atoms, while a compound is a pure substance made up of only one type of atom

• An element is a pure substance made up of only one type of atom, while a compound is a substance made up of two or more different types of atoms chemically bonded together.

Explain the concept of molarity.

• Molarity is the measure of the volume of a solution

• Molarity is the concentration of a solute in a solution, expressed as the number of moles of solute per liter of solution.

• Molarity is the measure of the acidity of a solution

• Molarity is the measure of the temperature of a solution

What is the difference between an exothermic and endothermic reaction?

• Exothermic reactions and endothermic reactions are the same

• Exothermic reactions release heat energy, while endothermic reactions absorb heat energy.

• Endothermic reactions release heat energy

• Exothermic reactions absorb heat energy

Describe the structure of an atom according to the Bohr model.

• Nucleus at the center with orbiting protons in energy levels

• Electrons at the center with orbiting nucleus in energy levels

• Nucleus at the center with orbiting neutrons in energy levels

• Nucleus at the center with orbiting electrons in energy levels

What is the significance of the periodic table in chemistry?

• It is a tool for mixing chemicals together

• It provides a framework for understanding the properties and behaviors of elements.

• It is a way to organize chemical equations

• It is used to calculate the atomic weight of elements

Explain the concept of electronegativity.

• Electronegativity is a measure of the tendency of an atom to repel a bonding pair of electrons.

• Electronegativity is a measure of the tendency of an atom to attract protons.

• Electronegativity is a measure of the tendency of an atom to lose electrons.

• Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.

What are the different types of chemical bonds?

• Polar bonds, nonpolar bonds, and ionic bonds

• Hydrogen bonds, ionic bonds, and covalent bonds

• Ionic bonds, covalent bonds, and metallic bonds

• Single bonds, double bonds, and triple bonds

Discuss the properties of acids and bases.

• Acids have sour taste, turn blue litmus paper red, and react with metals to produce hydrogen gas. Bases have bitter taste, turn red litmus paper blue, and feel slippery.

• Bases have sour taste, turn red litmus paper blue, and react with metals to produce hydrogen gas.

• Acids have sweet taste, turn blue litmus paper red, and feel slippery.

• Acids have bitter taste, turn red litmus paper blue, and feel slippery.