OBJECTIVE TYPE QUESTIONS:
Fill in the blanks:
________________ is the purest form of water.
Symbols are used for representing the ___________.
In filtration, the solid substance left behind on the filter paper is called________.
The symbol for sodium is__________.
The percentage of fresh water on earth is___________.
State True or False.
1. Oil spills do not harm marine life.
2. Increasing population is the leading cause of decreasing water table.
3. The symbol for potassium is P.
4. Saline water is fit for drinking.
5. A symbol is an abbreviation which represents one molecule of an element.
Match the following
Column A
Column B
Rain
Filtration
Sea water
Purest form of water.
A source of fresh water
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Residue
River
Alum
Salty
SUBJECTIVE TYPE QUESTIONS
Define: Water table, Chemical formula, Filtration.
Give reason for the following :
Water is essential for plant.
Water is known as the universal solvent.
Differentiate between: (i) Melting and Freezing (ii) Condensation and Boiling
(iii) Metal and Non-metal.
G. Answer the following question in details.
1. What are the effects of water pollution?
2. What are the main causes of water pollution?
Answers
Answer:
1. Rain water
2. elements
3. residue
4.Na
5. 3%
Define 1. The water table is an underground boundary between the soil surface and the area where groundwater saturates spaces between sediments and cracks in rock. Water pressure and atmospheric pressure are equal at this boundary. Underneath the water table is the saturated zone, where water fills all spaces between sediments
2.A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus and minus signs
3.Filtration is a process used to separate solids from liquids or gases using a filter medium that allows the fluid to pass through but not the solid. The term "filtration" applies whether the filter is mechanical, biological, or physical. The fluid that passes through the filter is called the filtrate.
Give reason 1. Water helps a plant by transporting important nutrients through the plant. Nutrients are drawn from the soil and used by the plant. Without enough water in the cells, the plants droop, so water helps a plant to stand. Water carries the dissolved sugar and other nutrients through the plant.
2. Water is called the "universal solvent" because it is capable of dissolving more substances than any other liquid. This is important to every living thing on earth. This allows the water molecule to become attracted to many other different types of molecules.
Differentiate between 1.Freezing is the change that occurs when a liquid changes into a solid as the temperature decreases. Melting is the opposite change, from a solid to a liquid as the temperature increases. These are both examples of changes in the states of matter of substances.
2. The boiling point of a substance is the temperature at which it changes from a liquid to a gas. The condensation point of a substance is the temperature at which it changes from a gas to a liquid. The boiling and condensation points of a substance are always equal.
3. Metals (like copper and aluminium) are good conductors of heat and electricity, while nonmetals (such as phosphorus and sulfur) are insulators.
G. 1. Diseases: In humans, drinking or consuming polluted water in any way has many disastrous effects on our health. It causes typhoid, cholera, hepatitis and various other diseases. Destruction of Ecosystems: Ecosystems are extremely dynamic and respond to even small changes in the environment
2. Runoff from Agricultural Operations.
Runoff and Nonpoint Source Pollution.
Industrial Activities.
Leakage from Underground Storage and Piping
Leaking Sewers.
Vehicle Emissions.
Landfill Leakage.
Hazardous Waste.