Science- Periodic Table And Elements

Question 1

How are chemical changes shown?

Answer 1

Chemical equations and symbol equations

Question 2

What is one way to show a chemical reaction?

Answer 2

Write a word equation e.g methane burns in oxygen giving carbon dioxide and water

Question 3

The chemicals on the left hand side of an word equation are the …

Answer 3

Reactants

Question 4

The chemicals on the right hand side in a word equation is called the

Answer 4

Products

Question 5

What do symbol equations show ?

Answer 5

They just show the symbols or formulas of the reactants and products

Question 6

Symbol equation 2Mg. + O2. ->2MgO

Question 7

What should symbol equations have the same of.

Answer 7

Number of atoms of each element on each side of the equation

Question 8

Symbol equations need to be balanced

Question 9

How would you balance this equation?
H2SO4. +2NaOH —->. Na2SO4 + H2O

Answer 9

As you can see there isn’t enough NaOH on the left hand side compared to the right side so you put a 2 in front of it (2NaOH) then it will balance the 2NaOH on both sides however as you can see there are less H and O on the right side and we can fix this by putting a 2 in front of the H2O on the rhs

Question 10

What does aqueous mean?

Answer 10

Dissolved in water

Question 11

What is located on the bottom left of a nuclear symbol?

Answer 11

Atomic number

Question 12

What is located on the top left of a nuclear symbol

Answer 12

Mass number

Question 13

What is the atomic number

Answer 13

It tells you how many protons the atom has.
Every atom of an element has the same number of protons

Question 14

For a neutral atom the number of protons is the same number of electrons

Question 15

What is the mass number

Answer 15

The total of protons and neutrons in the atom