GATE Questions

---

A substance that cannot be decomposed (broken down) into simpler substances by ordinary chemical means.

Examples: gold, iron, carbon, hydrogen, oxygen, nitrogen.

Material composed of only one kind of matter throughout (same atoms or same molecules).

Covalent bonds hold atoms together because the attraction between the positively charged nuclei and the negatively charged shared electrons is greater than the repulsions between the nuclei themselves.

Blood is a heterogeneous mixture because the blood cells are physically separate from the blood plasma. The cells have different properties than the plasma. The cells can be separated from the plasma by centrifuging, which is a physical change.

From solving 1 and 2 we get,

1.

5a(a-3)-3(a-3) = 0

(5a-3)(a-3) = 0

a = 3 or 3/5

2. 

3b(b+2)-1(b+2) = 0

b = -2 or b = 1/3

Here when a = 3, a > b for b = -2 and b = 1/3

when a = 3/5. a > b for b = -2 and b = 1/3.

Hence, it is clear that a > b. 

For undo the action or last action [Ctrl + Z] is used.

Albedo refers to a material's ability to reflect sunlight. Since 30% of the sun's energy is reflected by the entire earth, the earth has an average albedo of 0.30.

Generally, dark surfaces have a low albedo and light surfaces have a high albedo.