Scientists Discoveries

Question 1

What did John Dalton Discover?

Answer 1

• The properties of hydrogen and oxygen are very different than the properties of water
• The atom
• The atomic theory

Question 2

What did J.J. Thomson discover?

Answer 2

• Discovered the electron
• Proved Dalton’s model of the atom to be false (atoms CAN be divided into smaller particles)

Question 3

What did Ernest Rutherford discover?

Answer 3

• Discovered the nucleus and its positive charges as a result of the gold foil experiment

Question 4

What did Niels Bohr discover?

Answer 4

• Discovered electrons exist in energy shells/levels

Question 5

How many elements were on Medeleev’s periodic table?

Answer 5

60

Question 6

How many elements were on Moseley’s periodic table?

Answer 6

118

Question 7

How did Mendeleev arrange the elements on his periodic table?

Answer 7

In order of increasing atomic mass

Question 8

How did Moseley arrange the elements on his periodic table?

Answer 8

In order of increasing atomic number

Question 9

Is the period the horizontal row or the vertical column?

Answer 9

The horizontal row

Question 10

Is the group the horizontal row or the vertical column?

Answer 10

The vertical column

Question 11

How many periods are there on the periodic table?

Answer 11

7

Question 12

How many groups are there on the periodic table?

Answer 12

18

Question 13

Would elements in the same group or period have more physical or chemical properties in common?

Answer 13

Elements in the same group would have more similar chemical properties because they would all have the same number of valence electrons. However, elements in the same period have the same number of energy levels, so they would have more similar physical properties.

Question 14

Where are electrons (e-) located?

Answer 14

The energy shell.

Question 15

Where are protons (p+) located?

Answer 15

In the nucleus.

Question 16

Where are neutrons (n0) located?

Answer 16

In the nucleus.

Question 17

True or false: The number of neutrons = the atomic mass - the atomic number.

Answer 17

True

Question 18

What is a valence electron?

Answer 18

An electron that exists on the outer energy shell of an atom.

Question 19

Where are the alkali metals located?

Answer 19

In group 1 (except for hydrogen)

Question 20

Where are the alkaline earth metals located?

Answer 20

In group 2

Question 21

Where are the halogens located?

Answer 21

In group 17.

Question 22

Where are the noble gases located?

Answer 22

Group 18

Question 23

Where are the transition metals located?

Answer 23

Groups 3-12

Question 24

What are the properties of alkali metals?

Answer 24

• Low melting points
• Soft enough to be cut with a knife
• Highly reactive

Question 25

What are the properties of the alkaline earth metals?

Answer 25

- Highly reactive but less reactive than the alkali metals - Will burn in air if heated - Produce bright-coloured flames

Question 26

What are the properties of halogens?

Answer 26

- Highly reactive - Extremely corrosive - Melting point increases as you move from TOP to BOTTOM - Fluorine and chlorine are gases, bromine is a liquid, iodine is a solid

Question 27

What are the properties of noble gases?

Answer 27

- Odourless, colourless gases - Non-reactive elements (stable)

Question 28

What are the properties of metalloids?

Answer 28

Has some properties of metals and some properties of non-metals.

Question 29

What are the colour properties of metals and non-metals?

Answer 29

METALS: grey, dull colours, silver NON-METALS: various colours

Question 30

What are the state properties of metals and non-metals? (at room temp.)

Answer 30

METALS: solid (except for mercury (Hg)) NON-METALS: mainly gases, few solids, 1 liquid

Question 31

What are the lustre properties of metals and non-metals?

Answer 31

METALS: shiny NON-METALS: dull

Question 32

What are the conductivity properties of metals and non-metals?

Answer 32

METALS: conduct electricity NON-METALS: poor conductors

Question 33

What are the malleability properties of metals and non-metals?

Answer 33

METALS: malleable NON-METALS: non-malleable

Question 34

What are the ductility properties of metals and non-metals?

Answer 34

METALS: ductile NON-METALS: non-ductile

Question 35

What is the chemical formula?

Answer 35

The different elements the compound is composed of.

Question 36

what is the number beside O called in 02? / What’s the little number placed down and to the right of element symbols?

Answer 36

The subscript.

Question 37

what’s the number at the beginning of a compound?

Answer 37

The coefficient.

Question 38

what is NH3?

Answer 38

Ammonia

Question 39

what is 02?

Answer 39

Oxygen

Question 40

what is O3?

Answer 40

Ozone

Question 41

True or false: the protons and neutrons are in the same place in an atom?

Answer 41

True

Question 42

REMEMBER: The protons and Neutrons are IN the nucleus, so the nucleus is the (typically) dotted line surrounding the protons and neutrons.

Answer 42

Yes sir

Question 43

What is the calculation for the number of neutrons?

Answer 43

Atomic mass - Atomic number