M. Ncube

Grade 9. Go back to notes on chemical reactions and write balanced chemical equations for the following:
1.oxygen and a metal
2. Oxygen and a non-metal
3. Acid and base.
* Make your own choice of substances.

15:06/2020
Grade 9. Natural Sciences

Conduct a research on acid rain and write notes on;
-it’s formation
-its effects in stone statues
-its effects on crops.
(30 Marks)

When we dealt with micro-organisms we said disease causing organisms are pathogens. We also noted that some micro-organisms are good/helpful.

Make a list of all pathogenic micro-organisms and helpful micro-organisms. You have to give a reason why each pathogen is bad and the uses of each helpful micro-organism.
(30 Marks)

15/06/2020
Grade 10. AGRS
Weathering of rocks
——————-
Weathering is the breaking down of rocks into small pieces.

*Weathering is the main event in soil formation.
* Weathering helps in the release of plant nutrients that are contained in rocks.
*The weathering of rocks determines releases minerals that determine the mineral…[Read more]

15/06/2020
Grade 11. AGRS

PLANT NUTRITION: Water movement

1.Movement of water from the soil air int plant cells is through diffusion and osmosis.
Osmosis and diffusion are both passive absorption.

2.Active absorption occurs where energy from respiration is used.
3.A Hypertonic solution has a higher concentration of th solute. It is more…[Read more]

08/06/2020
Grade 9 Natural Sciences

The general reaction of an acid with a metal carbonate (base)
——————-___________
Metal carbonate are compounds that are bases. They can be used to neutralize acids. All carbonates include carbon trioxide. One atom of carbon goes with three atoms of oxygen.
Whenever an acid reacts with a metal…[Read more]

08/06/2020
Grade 8. Natural Sciences

Chemical reactions

When substances combine chemically or break chemically to form other substances we say they are reacting. Two or more substances that react are called reactants.
Example:

Substance A + Substance B —>New substance

Sodium + chlorine –> sodium chloride

During a chemical reaction,…[Read more]

08/06/2020
Grade 11 AGRS
Movement of water into and within the plant.

Water containing nutrients and carbohydrates moves from the roots to the stems and leaves by the process of transpiration. Transpiration ensures a constant upward movement of the mineral solution from the ground to the different parts of the plant.
Remember that the water…[Read more]

1. igneous rock soils
———————-
Examples of igneous rocks arequartz, dolorite, basalt and granite. Soils from these rocks are;
-sandy and not very fertile
-easily leached as percolating water washes minerals away.
-easily drained
-deep
-quit acidic
-suitable for deep rooted crops.

2.Sedimentary rock…[Read more]

04/06/2020
Grade 10

Research work
————–
Conduct a research on agricultural soils suitable for different food crops e.g. Cereals, tubers, citrus fruits, winter crops etc. Draw a table and match each crop with its suitable soil type.

Grade 11 04/06/2020
Plant nutrition

Like animals plants need nutrients to live. Unlike animals plants are autotrophic. They are able to use inorganic substances to make their own food. From the soil plants obtain mineral nutrients from the soil. These mineral nutrients are dissolved in water to form a mineral solution. The solution is…[Read more]

Grade 8. 03/06/2020
Natural Sciences

Written work
————-
1. The three states of matter are solid, liquid and gas.
1.1 List the solid, liquid and gas in order of:
1.1.1 least movement of particles to most movement of particles.
1.1.2 weakest forces between particles to strongest forces between particles.
1.1.3 smallest spaces between…[Read more]

3 June 2020. NS
Grade 8

You will need: White vinegar, an egg and a drinking glass.

The aim of this activity is to find out whether a chemical reaction will take place if you put an egg into white vinegar. Gather all the equipment that you need.

1Conduct your investigation.
(a) Place your egg carefully into the glass. Be careful not to…[Read more]

03/06/2020. NS
Grade 9

Work on your own.
Use words to write a summary for each of the following chemical reactions;
(a) metals with oxygen
(b) non-metals with oxygen
(c) acids with bases
(d) acids with metal oxides
(e) acids with metal hydroxides
(f) acids with metal carbonates,

03/06/2030. NS
GDADE 9

Work on your own.
Step 1. Use words to write a summary for each of the following chemical reactions;

(a) metals with oxygen
(b) non-metals with oxygen
(c) acids with bases
(d) acids with metal oxides
(e) acids with h metal hydroxides
(f) acids with metal carbonates

03/06/2020
Hrade 11 AGRS

Water and nutrients are taken up by roots from the soil.
The structure of the root
————————
-Meristematic zone is the root cap where new cells develop as the root grows downward away from light.
-Elongation zone is the area behind the root top.

-Root hair region is the place where absorption of water and…[Read more]

Quartz is found in sandy soils. It doesn’t undergo chemical reaction. Sandy soils;
-are not fertile
-easily lose minerals
-have a lot of macro pore
-are acidic.
– are suitable for deep-rooted plants.
^Quartz is formed from igneous rock.

Sedimentary rocks and cultivation
——————————–
Shale is made up of mud, clay and fine…[Read more]

30/05/2020
Grade 10. AGRS

THE MAIN ROCK TYPES IN SOUTH AFRICA
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1. Sandstone and shale are found in all the provinces of South Africa.
2.Dolorite is found in all the provinces of South Africa except Limpopo.
3.Greenstone is only found in Limpopo.
4.Granite is found in Eastern Cape, Western Cape, North West, Limpopo,…[Read more]

30/05/2020
Grade 11 AGRS

WATER AND NUTRIENTS
1.What is the importance of water in living things?
2. What is the importance of water in plants specifically?

If you attempt to answer the above questions you will be opened to a wealth functions of water.
Will hour water there can be no life on earth.
-It is the agent of chemical reactions in…[Read more]

29/05/2020
Grade 9. Natural Sciences

Rusting
——-
Many metals rust when exposed to moot air. Iron reacts with the oxygen that is dissolved in moisture to form a compound called rust. This rust easily peels off. The metal is corroded and weakened. Many structures, tools and machines are weakened or even collapsed by action of…[Read more]