Elements, compounds and mixtures

Question 1

What were the earliest scientists called?

Answer 1

Alchemists

Question 2

How many natural elements are there?

Answer 2

92

Question 3

How many artificial elements are there?

Answer 3

24

Question 4

What are the dangerous elements?

Answer 4

Sodium, potassium and mercury

Question 5

How do you determine the neutrons in an atom?

Answer 5

Neutrons = mass no. - atomic no.

Question 6

How many electrons does the first shell hold?

Answer 6

2

Question 7

How many can the 2nd and 3rd shell have? And how are they grouped?

Answer 7

8 maximum and they are grouped two together

Question 8

What are compounds?

Answer 8

Substance made up of two or more different types of atoms that have been bonded together.

Question 9

What is a mixture?

Answer 9

A combination of substances in which each keeps their own properties.

Question 10

What are protons?

Answer 10

Tiny
Heavy
Found in nucleus
Have a positive electrical charge

Question 11

What are electrons?

Answer 11

Very light
Negatively charged particles
Inside atom but circles the nucleus

Question 12

How do you determine the protons and electrons?

Answer 12

Protons and electrons = mass no.

Question 13

What are neutrons?

Answer 13

Tiny
Heavy
No electrical charge
Inside nucleus

Question 14

How do you separate a compound?

Answer 14

Passing electricity through it
Burning the compound
Mixing the compound

Question 15

What are the features of metals?

Answer 15

• solid at room temp
• can be polished
• good conductors of electricity and heat
• malleable
• ductile
• melts at high temps

Question 16

What are features of non-metals?

Answer 16

• they cannot be polished
• brittle
• not malleable or ductile
• poor conductors of heat and electricity
• melt at low temps

Question 17

What are metalloids?

Answer 17

Are elements that have features of both metals and non-metals

Question 18

Examples of metalloids

Answer 18

Boron
Silicon
Arsenic

Question 19

How many elements are non metal?

Answer 19

22

Question 20

What are the first 20 elements in the periodic table? and their signs?

Answer 20

hydrogen- H
helium- He
lithium- Li
beryllium- Be
boron- B
carbon- C
nitrogen- N
oxygen- O
fluorine- F
neon- Ne
sodium- Na
magnesium- Mg
aluminium- Al
silicon- Si
phosphorus-P
sulphur- S
chlorine- Cl
argon- Ar
potassium- P
calcium- Ca