Chemistry
(a) Name the three classes in which elements are classified. Which was the first metal used by man?
(b) Name the metal and non-metal present in abundance in the earth crust.
Answer
(a) The three classes in which elements are classified are –
- metals,
- non-metals and
- metalloids.
Copper was the first metal used by man for making utensils, weapons and for other purposes.
(b) The most abundant metal present in the earth’s crust is Aluminium and the most abundant non-metal present in the earth’s crust is Oxygen.
Related Questions
Name the metal which is a constituent of:
(a) blood pigment
(b) plant pigment
Give the importance of the following in living beings:
(a) Nitrogen
(b) Hydrogen
(c) Carbon
State the position of the following in the periodic table:
(a) Alkali metals
(b) Alkaline earth metals
(c) Halogens
(d) Aluminum
Name:
(a) a liquid non-metal
(b) two metalloids
(c) a metal which do not corrode easily
(d) two metals which react with cold water
(e) a non-metal which can form a positive ion.
(f) a non-metal which shows reducing property.