Hey everyone! Got two questions regarding significant figures:

1. If I'm using data from the data book, and the sig figs are lower than the ones in the question, which one should I follow?

(The question I'm on has 3 sig figs as the lowest number, but I'm also required to use the molar mass of hydrogen which is given in the data book as 1.0 which is 2 sig figs)

2. Can someone confirm if this is correct: (this is part of the working out for a larger question)

There's been a temperature change from 18.5 to 13.3 degrees Celsius. So delta T is 5.2 (one decimal place). The smallest number of significant figures given in the question is 3, but 5.2 has two significant figures. I'm now required to leave my answers to two significant figures instead of three because that's the lowest number of s.f in the working out, even if the question had 3 s.f.

Is this correct? This was a question on a practice SAC and I left my answer to 3 s.f., and lost a mark.

Thanks in advance!