In the equation 2 h2 + o2 -> 2h2o, h2, o2, and h2o are all trace elements. only h2o is a compound. only h2 and o2 are compounds. h2, o2, and h2o are all elements. h2, o2, and h2o are all compounds.

What is the approximate mass of 25 cm3 of silver, if the density is 10.5 g/cm3? a. 0.42 g b. 2.4 g c. 42 g d. 260 g

Apound is approximately 0.45 kilogram. a persons weighs 87 kilograms. what is the persons’s weight, in pounds, when expressed to the correct number of significant figures

Light travels through space at 186,282 miles per second and it takes about 1.3 seconds for light to travel from the moon to earth. which of the following is the correct method of finding the distance, in miles, between the moon and earth? add 186,282 and 1.3 divide 186,282 by 1.3 multiply 186,282 by 1.3 subtract 1.3 from 186,282