Which of the following measurements are recorded to three significant figures? Select all that apply. Select one or more:
a. 0.003 L
b. 140 g
c. 1,610 s
d. 0.0890 m

c) 1610 s

d) 0.0890 m

Explanation:

Significant figures:

The given measurement have four significant figures 1234.

All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.

Zero between the non zero digits are consider significant like 104 consist of three significant figures.

The zeros at the right side when decimal point is present e.g 2400. are also significant. There are four significant figures are present.

a) 0.003 L

This measurement have 1 significant figure which is 3.

b) 140 g

This measurement have 3 significant figure  1, 4. In this measurement 0 is trailing zero that's why it is not consider significant.

c) 1610 s

This measurement have 3 significant figures 1, 6, 1.

d) 0.0890 m

This measurement have 3 significant figures 8,9 and 0

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-