elements

Question 1

What are elements?

Answer 1

Elements are substances made up of only one type of atom which can’t be broken down into a simpler type of matter. There are about 116-117 types of element.

Question 2

What decides what type of atom is in the element?

Answer 2

The number of protons in its nucleus.

e. g -an atom with only one proton is hydrogen
- an atom with two protons is helium

Question 3

How are atoms of an element represented?

Answer 3

Through one or two letter symbols found on the periodic table.
e.g carbon=c
oxygen=o
sodium=Na

Question 4

What is an isotope?

Answer 4

An isotope is an atom with the same number of protons but a different number of neutrons so they have the same atomic number but different mass numbers.

Question 5

How would you describe an element with a number of isotopes?

Answer 5

Using relative atomic mass instead of mass number. This is an average mass.

Question 6

What is the formula for working out the relative atomic mass of an element?

Answer 6

relative atomic mass(A,)= sum of (isotope abundance x isotope mass number)
divided by
sum of abundances of all isotopes

Question 7

What is a compound?

Answer 7

A compound is a substance of two or more elements that have chemically combined.

Question 8

How are the atoms held together in a compound?

Answer 8

Through chemical bonding.

Question 9

How could you separate a compound?

Answer 9

By using a chemical reaction.

Question 10

How are compounds represented?

Answer 10

Compounds are represented by chemical formulas. Elements in a compound are represented by chemical symbols, and the ratio of different elements is represented by subscripts.

eg. H2O means two hydrogen atoms and one oxygen atom