Answer:
C. Soil
Explanation:
The choice with variable composition is the soil. Soil have many different composition.
- Soil is made up of minerals, organic matter , water and soil air.
- Soil minerals are derived from weathered bedrock materials that have been broken down into small pieces.
- Organic matter is derived from dead and decaying materials from plants and animals.
- All these materials combine together to form a soil.
Answer:
Peer review is a quality control measure for medical research. It
is a process in which professionals review each other's work to
make sure that it is accurate, relevant, and significant. Scientific
researchers aim to improve medical knowledge and find better
ways to treat disease.
if I am right mark the answer as brainliest
Answer:
Here's what I get
Explanation:
1. Sugar
(a) Dissolving in water
The white solid dissolves in water to give a colourless solution. There is no evidence that a new substance is being produced.
(b) Addition of sodium hydroxide
Adding the colourless solution of sodium hydroxide to the colourless sugar solution gives a colourless solution. There is no evidence that a new substance is being produced.
2. Magnesium sulfate
(a) Dissolving in water
The colourless crystals dissolve in water to give a colourless solution. There is no evidence that a new substance is being produced.
(b) Addition of sodium hydroxide
Adding the colourless solution of sodium hydroxide to the colourless solution of magnesium sulfate gives a white precipitate (see image). This is evidence that a new substance is being produced.
Explanation:
the answer and the working out is shown above, hope it helps.
Chemical change creates a new substance