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प्रश्न
You are given a hammer, a battery, a bulb, wires and a switch.
- How could you use them to distinguish between samples of metals and non-metals?
- Assess the usefulness of these tests in distinguishing between metals and non-metals.
उत्तर
- We can beat the sample with the hammer. If it can be beaten into thin sheets (that is, it is malleable), then it is a metal; otherwise, it is a non-metal. If the bulb glows the sample is metal, a good conductor of electricity. If, on the other hand, the bulb does not glow, the sample is non-metal, a bad conductor of electricity.
- Iron and many other metals are malleable and can be cast into sheets for roofing, trunks, boxes, and storage of articles of daily use. Metals are good conductors of electricity, so copper and aluminium wires are used for carrying electricity. The above tests are useful in distinguishing between metals and non-metals as they are based on their physical properties. No chemical reactions are involved in these tests.
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संबंधित प्रश्न
State why concentrated sulphuric acid is not used for drying ammonia gas
Why is ammonia gas not collected over water?
Name the most abundant non-metal in the earth's crust.
Name two metals which are both malleable and ductile.
Choose the acidic oxides, basic oxides and neutral oxides from the following:
Na2O; CO2; CO; SO2; MgO; N2O; H2O.
State three reasons (of which at least one must be chemical) for believing that sodium is a metal.
The electronic configurations of three elements A, B and C are as follows:
| A | 2, 8, 1 |
| B | 2, 8, 7 |
| C | 2, 4 |
(a) Which of these element is a metal?
(b) Which of these elements are non-metals?
(c) Which two elements will combine to form an ionic bond?
(d) Which two elements will combine to form a covalent bond?
(e) Which element will form an anion of valency 1?
Name the metals present in the following alloys
Duralumin
State any five physical properties of a metal.
Physical properties of a metal :
Name:
a metal with low melting and boiling points
Name:
a non metal which is lustrous
Give the balanced reactions for the following:
Sodium is dropped in water
Give the balanced reactions for the following:
Iron reacts with dilute HCI
The table below compares some properties of metals and non-metals. Write down the missing
statements (i) to (iv) :
| Metals | Non-metals |
| (i) ………………….. | Poor conductors of heat |
| (ii) Malleable | …………………… |
| (iii) Form positive ions | …………………… |
| (iv) ………………… | Form acidic oxides |
Which metal occurs as a halide also gives the name of their respective ore.
Oxygen, hydrogen, and sulphur are examples for
Tabulate the differences between metals and non-metals.
Which of the following non-metals is a liquid?
Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces. Which of the following is non-metal?
