Classify the following substances into elements, compounds and mixtures: (i) Cane sugar, (ii) Zinc, (iii) Oxygen (iv) Marble, (v) Bronze, (vi) Nitre, (vii) Air, (viii) Milk, (ix) Iron (x) Stainless steel.

Explain the following : (i) |x|=5 (ii) |x|=-5 (iii) |x|lt5 (iv) |x|lt-5 (v) |x|gt-5 (vi) |x|lt5

State with reasons, which of the following pairs of terms are of like terms and which are of unlike terms:(i) 7x, 12y(ii)15x, –21x(iii) – 4ab, 7ba(iv) 3xy, 3x(v) 6xy^2, 9x^2y (vii) mn^2, 10mn

Find out the number of significant figures in the following : (i) 247 (ii) 2609 (iii) 26500 (iv) 5.003 (v) 0.00692 (vi) 0.6790 (vii) 2.42xx10^(-2) (viii) 60000

When we add zero to any whole number we get the same whole number Zero is called the additive identity for whole numbers .Is it an additive identity again for integers also Observe the following and fill in the blanks (i) (-8)+0=-8 (ii) 0+(-8)=-8 (iii) (-23) +0= (iv) 0+(-37)=-37 (v) 0+(-59)=... (vi) 0+...=-43 (vii) -61 +....=-43 (vii) -61 +...=-61 (viii) ..+0= ..... The above examples shows that zero is an additive identity for integers . you can verify it by a adding zero to any other five integers . In general , for any integer a , a+0=0+a=a

Which of the following are pure substances and which are mixtures ? Air, Milk,Graphite,Gasoline,Distilled water,Ice,Iodised table salt,Oxygen,One rupee coin, 22 carat gold,24 carat gold,Steel,Iron,Solid iodine.