Unit B Section 2.2

Question 1

List five properties used in describing an element.

Answer 1

• Colour
• State
• Appearance (Shine or texture)
• Hardness
• Magnetism
• Electrical Conductivity

Question 2

How many elements have been discovered?

Answer 2

scientists have identified 112 elements.

Question 3

By the early 1800s, more than

30 elements had been identified, including oxygen, lead, and mercury.

Answer 3

-

Question 4

a better system for organizing the elements was made by John Dalton, an English chemist.

Answer 4

-

Question 5

How did John Dalton make the metal elements organized?

Answer 5

The symbols for the Sun and planets closest

to Earth have long been used to represent the seven metals known from ancient times

Question 6

Metal symbols with plants and celestial bodies

Answer 6

- Sun= Gold 
Moon= Silver
Mars=Iron
Jupiter= tin
 Venus=Copper
Saturn= Lead

Question 7

What did Swedish chemist Jöns Jacob

Berzelius do?

Answer 7

In 1814, Berzelius suggested using letters rather than pictures to represent each element.

Capitalized the first letter of the element

Question 8

How are elements listed in order?

Answer 8

listed in order of increasing atomic mass

Question 9

What is an atomic mass?

Answer 9

Atomic mass is the mass of one atom of an
element.

Equivalent to the number of protons and neutrons in the atom.

atomic mass unit (AMU)

determine the average mass of an atom of
other elements by comparing it with the mass of a carbon atom

Question 10

What did John Newlands do?

Answer 10

recognized a pattern when elements were listed by increasing atomic mass.

He noticed that properties of elements seemed to repeat through this list at regular intervals. He called this pattern the “law of octaves,”

Question 11

What is the law of octaves

Answer 11

properties of elements seemed to repeat through this list at regular intervals.

octave scale on a piano or other musical instrument

Question 12

What did Russian chemist Dmitri Mendeleev do?

Answer 12

organize the elements in a way that reflected the patterns in the properties of the elements.

Used cards to sort the elements into a pattern
based on their properties

wanted to find a pattern that would allow him to predict the properties of elements not yet discovered
This would prove that his pattern works

Question 13

Element circle symbols:

Answer 13

• hydrogen
• oxygen
• carbon
• gold
• silver
• mercury