GRADE 9 NATURAL SCIENCE EXAM
QUESTIONS AND CORRECT ANSWERS
What happens if you burn a piece of wood with oxygen ? - ANSWER-- it combines with
oxygen
- changes colour
- carbon dioxide and water vapor is released
- gases floats into the air
What is combustion? - ANSWER-the process of burning something
Compound - ANSWER-A substance made up of two or more different elements joined
by chemical bonds
How to neutralize something ? - ANSWER-Use a weak acid to neutralize bases
properties of bases - ANSWER-taste bitter
slippery to the touch
can be poisonous & corrosive
release OH- ions in water
properties of acids - ANSWER-- sour taste
- turn blue litmus paper red, keep red litmus paper red
- ph < 7
- feels rough
Balancing Equations - ANSWER-The mass and the charge are balanced on both sides
of the reaction
What is a group? - ANSWER-Vertical column in the periodic table
What is a period? - ANSWER-horizontal row in the periodic table
Reactions - ANSWER-in reaction, energy is released or absorbed
Neutralization - ANSWER-A reaction between an acid and a base
Rusting - ANSWER-happens when metal reacts to oxygen
Nucleon - ANSWER-protons, neutrons and electrons
Sodium - ANSWER-Na
carbon dioxide - ANSWER-CO2
QUESTIONS AND CORRECT ANSWERS
What happens if you burn a piece of wood with oxygen ? - ANSWER-- it combines with
oxygen
- changes colour
- carbon dioxide and water vapor is released
- gases floats into the air
What is combustion? - ANSWER-the process of burning something
Compound - ANSWER-A substance made up of two or more different elements joined
by chemical bonds
How to neutralize something ? - ANSWER-Use a weak acid to neutralize bases
properties of bases - ANSWER-taste bitter
slippery to the touch
can be poisonous & corrosive
release OH- ions in water
properties of acids - ANSWER-- sour taste
- turn blue litmus paper red, keep red litmus paper red
- ph < 7
- feels rough
Balancing Equations - ANSWER-The mass and the charge are balanced on both sides
of the reaction
What is a group? - ANSWER-Vertical column in the periodic table
What is a period? - ANSWER-horizontal row in the periodic table
Reactions - ANSWER-in reaction, energy is released or absorbed
Neutralization - ANSWER-A reaction between an acid and a base
Rusting - ANSWER-happens when metal reacts to oxygen
Nucleon - ANSWER-protons, neutrons and electrons
Sodium - ANSWER-Na
carbon dioxide - ANSWER-CO2
