Question

class 8 science chapter 4 summary​

Answer 1

Answer:

Today's worksheet of maths chp 5. Page no 62 do it in book and copy with date and cw and in a good handwriting.

Answer 2

Explanation:

Physical Properties of Metals:

Metals are:

hard to touch.

lustrous i.e., freshly Cut surfaces of metals have characteristic shining.

malleable; the property of metals by which they can be beaten mW thin sheets is called malleability.

ductile; the property of metal by which it can be drawn into wires is called ductility.

sonorous i.e., metals produce ringing sound when struck on a hard surface.

Good conductors of heat and electricity.

Metals like sodium and potassium are soft and can be cut with a knife.

Mercury is the only metal which is found in the liquid state at room temperature.

Physical Properties of Non-metals:

Non-metals are soft and dull (e.g., coal and sulphur).

Non-metals are generally brittle, i.e., they break down into a powdery mass on tapping with a hammer.

They are not sonorous.

They are poor conductors of heat and electricity.

Chemical Properties of Metals and Non-metals:

Reaction with Oxygen: Both metals and non-metals when burnt in oxygen from their oxides. Oxides of metals are basic in nature while that of non-metals are generally acidic in nature e.g.,

Materials Metals and Non-Metals Class 8 Notes Science Chapter 4 1

Reaction with Water: Some metals react with water to produce metal hydroxide and hydrogen gas. Generally, non-metals do not react with water