Question

a polythene contains copper powder of mass 15.64 x -0.2 g some of the powder of mass 6.23 x 0.1 g is taken out mass of powder left back is

Answer 1

To find the mass of copper powder left in the polythene, the mass taken out (approx. 7.84 g) is subtracted from the original mass (approx. 9.86 g), resulting in approximately 2.02 g remaining.

Step-by-step explanation:

The mass of copper powder originally in the polythene is 15.64 x 10-0.2 g. After removing some of the powder with a mass of 6.23 x 100.1 g, to find the mass of copper powder left back, we subtract these two values. First, we need to convert the scientific notation to standard decimal form as follows:

• 15.64 x 10-0.2 = 15.64 / (100.2) = 15.64 / 1.58489 ≈ 9.86 g (approximately)
• 6.23 x 100.1 = 6.23 x (100.1) = 6.23 x 1.25893 ≈ 7.84 g (approximately)

Now we subtract the second mass from the first to find the remaining mass:

9.86 g - 7.84 g = 2.02 g

The mass of the copper powder left back in the polythene is approximately 2.02 g.