L2

Question 1

What is mass in chemistry?

Answer 1

How much matter is in an object. It is also known as atomic mass.

Question 2

What mass does a proton have?

Answer 2

A relative mass of 1.

Question 3

How much mass does a neutron have?

Answer 3

A relative mass of 1.

Question 4

How much mass does an electron have?

Answer 4

A relative mass of 0.

Question 5

What is charge?

Answer 5

If atoms are neutral, this means they don’t have charge. When an atom is chemically bonded with another atom, it is possible it will lose or gain an electrons, making it positively or negatively charged. We don’t call this an atom anymore, it will be called an ion.

Question 6

How is mass found?

Answer 6

When you add the amount of protons with the amount of neutrons.

Question 7

How is the total charge of protons found in an atom?

Answer 7

The amount of protons in an atom is the total charge of protons in the atom - this is always recorded with a ‘+’ sign because protons are positively charged.

Question 8

How is the total charge of neutrons found in an atom?

Answer 8

The total charge of neutrons in an atom is always 0 because neutrons don’t have any charge as they’re neutral.

Question 9

How is the total charge of electrons found in an atom?

Answer 9

The amount of electrons in an atom is the total charge of electrons in the atom - this is always recorded with a ‘-‘ sign because electrons are negatively charged.

Question 10

What was the first theory of how the atom looked like?

Answer 10

In 400bc, a man named Democritus came up with the solid sphere model.

Question 11

What was the second theory of how the atom looked like?

Answer 11

In 1803, a man named John Dalton continued the solid sphere model.

Question 12

What was the third theory of how the atom looked like?

Answer 12

In 1897, a man named JJ Thomson discovered the electron. And later, in 1904, he came up with the plum pudding model.

Question 13

What was the fourth theory of how the atom looked like?

Answer 13

In 1908, he discovered the nucleus. In 1911, a man named Ernest Rutherford came up with the nuclear model.

Question 14

What was the fifth theory of how the atom looked like?

Answer 14

In 1913, a man named Niels Bohr came up with the planetary model.

Question 15

What was the sixth theory of how the atom looked like?

Answer 15

In 1926, a man named Erwin Schrodinger came up with the quantum model.

Question 16

What was the seventh and most recent theory of how the atom looked like?

Answer 16

In 1932, a man named James Chadwick came up with the Rutherford-Bohr model.

Question 17

What did Democritus think about the atom?

Answer 17

He thought that everything was made up of the exact same solid spheres, there is only one type of atom. ‘Atoms’ - indivisible.

Question 18

What did John Dalton think about the atom?

Answer 18

Substances were made of atoms that were like tiny, hard spheres. Different substances were made up of atoms that had a different mass and appearance and atoms of the same element/substance have the exact same appearance and mass. He also thought there was heat as an atmosphere or a blanket of subtle fluid around the atom.

Question 19

What did J.J. Thomson think about the atom?

Answer 19

He thought the atom was made up of tiny electrons. Because atoms have no overall charge they must also have positive charges to balance out the negatively charged electrons. Atoms were likened to a plum pudding, with electrons (plums) embedded in a positively charged sphere (the pudding). He discovered the electron.

Question 20

What did Ernest Rutherford think about the atom?

Answer 20

There was a positive charge in the centre of the atom that was concentrated into a tiny spot called the nucleus. he found this out by firing alpha particle at very thin, gold foil; most of them passed through but very few of them bounced off. The nucleus is orbited by negative electrons. He discovered the proton and nucleus.

Question 21

What did Niels Bohr think about the atom?

Answer 21

Electrons must orbit the nucleus at set distances in certain, fixed energy levels called shells. Not all electrons in an atom will have the same amount of energy as they exist in different shells at distances from the nucleus. He discovered the shells.

Question 22

What did Erwin shrodinger think about the atom?

Answer 22

Electrons don’t move in set paths around the nucleus, but in waves. It is impossible to know the exact location of the electrons; instead we have ‘clouds of probability’ called orbitals, in which we are more likely to find an electron.

Question 23

What did James Chadwick think about the atom?

Answer 23

There are neutral particles called neutrons in the nucleus of an atom in addition to the protons. The electrons are held by the shells.

Question 24

What was the order of discovery for the subatomic atoms?

Answer 24

Electrons, protons and neutrons.

Question 25

Why was the neutrons the last to be discovered?

Answer 25

Since they’re neutral (meaning they don’t have an electrical charge) it made them harder to detect.