ASAP will give brainliest <3
1. What is the calculated empirical formula of the copper oxide if a 0.626 g sample of the copper oxide was reduced to 0.500 g of copper metal by heating in a stream of hydrogen gas?
2. If a sample of salt water has a measured concentration of 21.0 ppt, how many grams of salt are there in a 2.05 kg sample of this salt water?

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.

answer; the numbers of valence electrons in the acetic acid molecule (ch3co2h) is 24;