Metals are extracted from their ores.

Many copper ores contain only 2% of copper compounds.

Copper is now extracted from ores containing a low percentage of copper compounds.

Suggest two reasons why.

What is the chemical formula for tin (II) fluoride?

How many formula units make up 24.2 g of magnesium chloride (MgCl2) ?

Do you expect to find an atom with 26 protons and mass number 52

A 2.0 L flexible container holds 5.0 moles of oxygen (O2) gas. An additional 15.0 moles of nitrogen gas (N2) is added to the container. What is the new volume of the container?

According to the rock cycle, which of the following transitions are possible? Assume an unlimited number of steps. (A) An intrusive igneous rock becomes a sedimentary rock. (B) A sedimentary rock becomes soil.

Which physical method can be used for obtaining a sample of salt from a small beaker of salt water? boiling freezing chromatography sorting

Science is a unique field of thought because it relies on to describe the world. •Observations and experim •Teachers and students •Books and writings •Scientists and statements

Hemoglobin, a protein in red blood cells, carries o2 from the lungs to the body's cells. iron (as ferrous ion, fe2+) makes up 0.33 mass % of hemoglobin. if the molar mass of hemoglobin is 6.8 Ã 104 g/mol, how many fe2 + ions are in one molecule?

What could you predict about a methane molecule that would most likely be made by using both the quantum model of the atom and John Dalton's model?

What is the molar mass of an unknown hydrocarbon whose density is measured to be 1.97 g/l at stp?