ASSIGNMENT-4- IS MATTER AROUND US PURE:
Q-1) Gold can be drawn in wire. Name the property.
Q-2) between sulphur and copper which one you will use for making wire.
Q-3) silver is best conductor of electricity still electrical wires are made of
copper and aluminium. Why?
Q-4) 1. Name a soft metal.
2. Name the element present in diamond.
3. Name a non-metal having shining surface.
4. Name an element used as semi-conductor.
Q-5) Why metals are used in making instruments like bells, tanpura and violin?
Q-6) Why metalloids are used as semi-conductor?
Q-7) Non-metals are bas conductor of electricity. Name a non-metal which is
conductor of electricity and is used in making electrodes.
Q-8) Is Diamond element or compound? Write its composition.
Q-9) Non-metal are usually soft. Do you know any hard non-metal? If yes,
name it.
Q-10) Why water is a compound not a mixture?
Q-11) Which of the following will show properties of its constituents?
Methane or soil.
Q-12) Name solute in brass
Q-13) Particle size of a substance was 50 mm. Is solution or colloid or
suspension?
ANSWER DO
Answers
Answer:
1)ductility
2)copper
3)low cost
4)gold
carbon
mercury
carbon
5)sonarity
7)copper
Answer:
1) ductility
2) copper
3) silver is best conductor of electricity but it is costly . copper and aluminium have low resistance and excellent conductive , hence they are used in place of silver .
4) 1. sodium
2. carbon
3. graphite
4. silicon
5) metals are used to make instruments like bells , tanpura and violen is because the property of metals to make sound ( sonorous ) makes the instruments produce sounds .
6) metelloids are used as semi conductor is because their electrons are more tightly bound to their nuclei than of those of metallic conductors .
7) graphite
8) diamond is made out of pure carbon, thus it is made up of an element but diamond itself is not an element or a compound .
composition : carbon atoms are arranged in cubic structure and bonded to every atom in a compact manner .
9) diamond is the hardest non metal
10)water is a compound and not a mixture because it is made up of only one kind of element that is oxygen and hydrogen atoms which makes it a diatomic molecule.
11) soil
12)copper
13)it is colloidal solution because the size of the particle should be less then 1 nm to fall in solution catagory or the size should be more than 1000 nm to fall in suspension catagory.