Chapter 2

Question 1

In 5th century BC, Leucippus and Democritus discovered?

Answer 1

Atoms

Question 2

In 5th century BC, Aristotle and Plato discovered?

Answer 2

Earth, air, fire and water

Question 3

The 16th century was known as the?

Answer 3

Scientists revolution

Question 4

What scientist were a part of the scientists revolution?

Answer 4

Copernicus, Bacon, Kepler, Galileo, Boyle and Newton

Question 5

In the 17th century Dalton created?

Answer 5

The atomic theory of matter

Question 6

What is the law of conservation of mass?

Answer 6

In a chemical reaction, matter is neither created or destroyed, it is conserved

Question 7

What is the law of definite proportions?

Answer 7

All samples of a given compound, regardless of their source or how they were prepared, have the same proportions of their primary elements

Question 8

What is the law of multiple proportions?

Answer 8

When two elements (A + B) form two different compounds, the masses of B that combine with 1g of element A can be expressed as a ratio of small whole numbers

Question 9

What is the Atomic Theory created by John Dalton

Answer 9

1. Each element is composed of tiny, indestructible particles called atoms
2. All atoms of a given element have the same mass and other properties that distinguish them from other atoms of other elements
3. Atoms combine in simple, whole-number ratios to form compounds
4. Atoms of one element cannot change into atoms of another element. In a chemical reaction, atoms only change the way they are bound together with other atoms

Question 10

What are electrostatic forces?

Answer 10

Attractive and repulsive forces between particles

Question 11

What are the discovery of the electrons?

Answer 11

Cathode ray: a beam of particles travels from the negatively charge electrode (cathode) to the positively charged one (anode) they carried a negative electrical charge

Question 12

What is scanning tunnelling microscopy?

Answer 12

A technique where an automatic sharp tip is scanned across a conducting surface, by moving it up and down to maintain a constant tunnelling current. The tip motion is recorded to create an image of the surface with automatic resolution

Question 13

A single Bond consists of?

Answer 13

One sigma bond

Question 14

A double done consists of?

Answer 14

One sigma bond and one Pi bond

Question 15

A triple bond consists of?

Answer 15

One sigma bond and two Pi bonds