How many protons, neutrons, and electrons are in an atom of hydrogen with an atomic number of 1 and a mass number of 3

Asample of rose gold is: 12.0 g gold, 5.0g silver, and 7.0 g copper. what is the percent copper in the sample?

In the 1800s, one of the statements in john dalton's atomic theory was that atoms are indivisible. later experimental evidence led to the discovery of subatomic particles such as neutrons, electrons, and protons. what happened to the indivisible atom part of dalton's atomic theory, and why?

How have the greenhouse gasses increased from the year 2000 to 2018