(c) 21.23 ml (d) 21.232 ml
q3. how many significant figures are in the number 0.00620?
(a) 2 (b) 3
(c) 4
(d) 5
q12.

b). 3

Explanation:

every real number is a sig fig (1-9)

Any zeros after real numbers behind the decimal are sig figs (0.340 = 3 sig figs)

Any zeros in between real numbers are sig figs (3402 = 4 sig figs)

If there is a clear decimal, every number in front of it are sig figs (100. = 3 sig figs) - this can also be expressed by a line above the zeros

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).