We have to convert 0.18 km into feet
First, we need to know the conversions:
1 inch = 2.54 cm (exact)
1 pound = 454 g
1 Liter = 1.0b quarts
1 feet = 12 inches
1 galion = 4 quarts
1 pound = 16 ounces
0.18 km x (1 feet/12 inches) x (1 inch/2.54cm) x (1000 m/1 km) x (100 cm/1 m) = 590 ft
Answer: 590 ft (2 significant figures)
Percentage
by mass is the amount in mass of a component in a mixture per 100 unit of mass of the total
mixture. Percentage by mass is the same as %w/w. In order to determine this value, we need to know the mass of the substance in question and the total mass of the sample. In this case, we have to know the mass of Fe by doing certain calculations. Then, we divide this value by the total mass given of the ore, 4.05 g and multiply by 100%. It should be expressed as follows:
Percent by mass = mass of Fe in ore / 4.05 g ore sample x 100
However, the question is lacking some information so we cannot really specify the answer.
Are you referring to which element that has the same reactive properties? If so it would be any element in the Chalcogen group.
