An element's atomic number is 87. how many protons would an atom of this element have

How much gold is harvested per ton of earth from the underground mine?

Which has the greater number of particles, 1 mole br2 or 80g br2?

A mixture of h2 and n2 has a density of 0.216 at 300k and 500 torr. what is the mole fraction composition of the mixture

The density of copper is 8.96g/ml. the mass of 7.00ml of copper is

Write and balance the chemical equation for the reaction between carbon monoxide, co (g), and oxygen to form carbon dioxide, co2 (g). use only integers (not fractions) and be sure to include the states of matter.

100 ml oxygen at 1.75 atm and 200ml nitrogen at 0.6 atm are passed to a 500 ml vessel. Calculate the total pressure of the mixture in the vessel at same temperature

Which is the best metal to use in an alloy to increase its electrical conductivity

Ice does not need to melt into liquid water before it can return to the atmosphere as water vapor. a. True b. False

How much ice at a temperature of - 17.5 ∘C must be dropped into the water so that the final temperature of the system will be 31.0 ∘C?

Why does a gas fill completely the vessel in which it is kept?