Significant figure of 87 000 ms

2 significant figures.

Explanation:

Significant Figures Rules:

1. Anything that isn't a zero is a sig fig

2. If a decimal point comes after the ones digit, everything before the decimal is counted as sig fig (i.e 2000. would be 4 sig figs).

3. If we are dealing with small decimals, the zero before and after the decimal (i.e 0.002) is a placeholder and is not counted as sig figs.

4. Any zeros between 2 significant digits is considered in sig figs (i.e 2002 would be 4 sig figs)

Since we are dealing with 87000, we see that we have no decimal point. That means our only sig figs are 8 and 7, which equals 2 sig figs.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e