Atoms and Molecules

Question 1

Law of Chemical Combination

Answer 1

• Law of Conservation of Mass
• Law of Constant / Definite Proportions

Question 2

Law of Conservation of Mass

Answer 2

Law of Conservation of Mass states that mass can neither be created nor be destroyed in a chemical reaction.
(i.e.) Mass of Reactants = Mass of Products

Question 3

Law of Constant / Definite Proportions

Answer 3

Law of Constant / Definite Proportions states that,

• In a chemical substance the elements are always present in definite proportions by mass.
  Example: In pure water (H2O), the Ratio of Hydrogen : Oxygen is 1:8

Question 4

All matter is made of…

Daltons Atomic Theory

Answer 4

All matter is made of very tiny particles called atoms, which participate in chemical reactions.

Question 5

Atoms are…

Daltons Atomic Theory

Answer 5

Atoms are indivisible particles, which cannot be created or destroyed in chemical reactions.

Question 6

Atoms of a given element are…

Daltons Atomic Theory

Answer 6

Atoms of a given element are identical in mass and chemical properties.

Question 7

Atoms of different elements have…

Daltons Atomic Theory

Answer 7

Atoms of different elements have different masses and chemical properties.

Question 8

Atoms combine in…

Daltons Atomic Theory

Answer 8

Atoms combine in the ratio of small whole numbers to form compounds.

Question 9

The relative number and kinds of atoms…

Daltons Atomic Theory

Answer 9

The relative number and kinds of atoms are constant in a given compound

Question 10

What is an Atom?

Answer 10

Atoms are the building blocks of all matter.