Compare the mass number and atomic number for isotopes of an element

Ammonia (nh3) is widely used as a fertilizer and in many household cleaners. how much ammonia is produced when 6.64 mol of hydrogen gas react with an excess of nitrogen gas

Iron bromide is ionic. What is the charge on the bromide ion

A neutral atom contains 5 neutrons and 4 protons. How many electrons does it contain?

How is momentum conserved in a system wich two satellites connect

When Dmitri Mendeleev published his periodic table of the elements in 1869, there were 59 known elements. Today there are 118 known elements.

Calculate the density of a rectangular solid that has a mass of 25.71 g, and its dimensions are 2.3 x 4.01 x 1.82 cm.

When the metal sample reacts with acid, the gas evolved will be collected over water; the gas is said to be "wet".

Solid iron (II) sulfide reacts with aqueous hydrochloric acid HCl to produce hydrogen sulfide gas H2S and aqueous iron (II) chloride.

How are mixtures compounds and elements alike?

The percentage of carbon dioxide in the atmosphere has increased in the last century and is a concern for the environment as it increases the greenhouse effect. Give one possible explanation for the increase of carbon dioxide in the atmosphere