Three - all nonzero numbers are significant.
3 of them.
5 significant figures.
Rounded to two significant figures, 7.42 grams is approximately equal to 7.4 grams.
4 of them.
5
302.05 grams
5 significant figures.
There are 3 significant figures in '4.50g'
The 3 and the 2.
Rounded to two significant figures, 7.42 grams is approximately equal to 7.4 grams.
There are four significant figures in 33050. The trailing zero is not significant because there is no decimal. There would be five significant figures in 33050. If we were to remove the last zero in the number, we would alter the value of the number. Had the number been 3305.0, then there would have been four significant digits.
The significant figures are the ones which convey meaningful information about the measurement beyond the magnitude. Saying that a sample weighs .0000039 grams is better stated as 3.9 x 10^-6 grams or perhaps 3.9 micrograms. That's two significant figures. All the zeroes are not significant.
Three of them.
302.5 grams
302.05 grams
4 of them.
From the periodic table, 1 mole of sodium is 22.989770g. To find the number of moles in 2.30g, multiply the known mass x (1mol/22.989770g). 2.30g Na X (1mol Na/22.989770g Na) = 0.100mol Na* * The answer is in 3 significant figures because 2.30g has 3 significant figures. When you multiply or divide, the answer is rounded to the same number of significant figures as are found in the number with the fewest significant figures.
There are 4 significant figures in this problem.