How do you calculate the percent by mass of an element in a compound?

Identify the spectator ion (s) in the following reaction: MgCO3 (s) + H2SO4--> MgSO4 (aq) + H2O (l) + CO2

The measurement 12.0 km contains significant figures

What is the pressure of a mixture of nitrogen (N2) and oxygen (O2) if partial pressure of N2 is 594 mm Hg and the partial pressure of O2 is 165 mm Hg?

Which is the preserved evidence of the activity of an organism?

Tin has many possible isotopes. three of these isotopes are 115sn, 117sn, and 126sn. what is the mass number of each? how many protons, neutrons, and electrons are present in each?

An object is dropped onto the moon (g m = 5 ft/s 2). how long does it take to fall from an elevation of 250 ft.?

Which type of luster gives the mineral the appearance of metal?

Anything that contains only one kind of material?

One mole of propane (c3h8) gas reacts with five moles of oxygen (o2) gas to produce three moles of carbon dioxide gas (co2) and four moles of water gas (h2o).

How many nitrogen molecules are in 1.2 moles of N2?