Chemistry Elements

Question 1

What is an Element?

Answer 1

A pure substance made up of one type of atom.

Question 2

How many elements occur naturally?

Answer 2

98

Question 3

How many elements are man-made?

Answer 3

20

Question 4

Name three elements in a smart phone

Answer 4

Gold
Lithium
Tin

Question 5

What is a chemical symbol?

Answer 5

A one or two letter code for an element.
Scientists all over the world use them.
Some codes come from there latin names e.g Au for Gold

Question 6

What is an Atom?

Answer 6

The smallest part of an element that exists. can either be Negatively or Positively charged.

Question 7

The smallest part of an element that can exist is called an ____.

Answer 7

Atom

Question 8

All Atoms of an element are the ____.

Answer 8

Same

Question 9

The atoms of one element are _________ to the atoms of another element

Answer 9

Different

Question 10

What is a compound?

Answer 10

A pure substance made of atoms of two or more elements. The atoms are strongly joined together.
The atoms are chemically bonded. E.g H2O: Water

Question 11

What is a molecule?

Answer 11

A molecule is a group of two or more atoms strongly joined together. Most non-metals and compounds of non-metals, exist as small or giant molecules
E.g Oxygen,Hydrogen, Water.

Question 12

Why does salt not smell or poison you or make your mouth fizz?

Answer 12

In salt, the atoms of sodium and chlorine, are not just mixed up.
They are joined together to make one substance called sodium chloride.
This compound has different properties than the elements in it.

Question 13

Carbon Dioxide has __ grams of carbon for every __ grams of Oxygen

Answer 13

12
32

Question 14

Carbon Monoxide has __ grams of carbon for every __ grams of Oxygen

Answer 14

12
16

Question 15

Compounds made up of Oxygen and another element have two word names. the second word is _____.

Answer 15

Oxide

Question 16

Name the compound of Sodium and Chlorine.

Answer 16

Sodium Chloride.

Question 17

What is a Chemical formula?

Answer 17

A chemical formula shows the elements present in a compound. It also shows the relative number of atoms of each element in the compound.

Question 18

What is the relative number?

Answer 18

It shows how many of one type of atom there is compared to another.
E.g. Carbon Dioxide is CO2. This shows there is one carbon atom for every two oxygen atoms.

Question 19

A hydroxide includes ________ and ______ atoms.

Answer 19

Hydrogen and Oxygen
The formula of sodium hydroxide is NaOH

Question 20

A nitrate includes ________and ______ atoms.

Answer 20

Nitrogen and Oxygen
The formula of sodium nitrate is NaNO3.

Question 21

A sulfate includes ______ and ______ atoms.

Answer 21

Sulfur and Oxygen
The formula of copper sulfate is CuSO4

Question 23

A carbonate includes ______ and ______ atoms.

Answer 23

Carbon and Oxygen
The formula of calcium carbonate is CaCO3

Question 24

Write down three elements that make up Copper Sulfate.

Answer 24

Copper
Oxygen
Sulfur

Question 25

What does a chemical formula show?

Answer 25

The elements present in a compound. It also shows the relative number of atoms of each element.

Question 26

What is the relative number of an atom?

Answer 26

Relative number means how many of one type of atom there are compared to others. Eg: CO2 - carbon dioxide. One Carbon atom for every two oxygen atoms.

Question 27

What are polymers?

Answer 27

A polymer is a substance with very long molecules. A polymer molecule has identical groups of atoms, repeated many times.

Question 28

Name some natural polymers.

Answer 28

Wool - sheep make wool. Wool fibres trap air between them. Rubber trees - make rubber. Rubber molecules are long and bendy so they can slide over each other. So rubber is flexible, waterproof and durable. These properties make it suitable for tyres.

Question 29

Name some synthetic polymers.

Answer 29

Plastics such as poly(ethene) and PVC.

Question 30

What is poly(ethene)?

Answer 30

It is the scientific name for polythene LDPE - low density poly(ethene) molecules slide over one another - makes it flexible. LDPE is strong. Used for carrier bags. HDPE - high density PE is harder and LDPE. Its surfaces can be very smooth. Is used in artificial knee joints, which also include metal such as titanium.

Question 31

Does poly(ethene) break down?

Answer 31

No, it does not wear down or break down (decay) naturally. This is important for artificial knee joints but makes it hard to get rid of carrier bags.

Question 32

How do polymer properties depend on their molecules?

Answer 32

Polymer molecules are relative big and heavy. This means that they melt at higher temperatures than substances with smaller molecules.

Question 33

What is the periodic table?

Answer 33

Shows all the elements, grouped together with similar properties.

Question 34

In the periodic table, vertical columns are called..

Answer 34

groups

Question 35

In the periodic table, horizontal columns are called...

Answer 35

periods.