What is the percent by mass of oxygen in Fe2O3 (formula mass = 160) ?

How do we use properties of matter in our every day lives

What happens when light strikes an opaque object? A) All of the light passes through the object. B) All of the light is reflected by the object. C) None of the light passes through the object.

Which atom has the weakest attraction for electrons in a chemical bond?

Rita was sitting in the garden and reading a book a sudden breeze went by her and she sneezed this reaction is a type of __? action (involuntary, voluntary) In this case Rita's response was controlled by her___? (brain heart or nerves)

Parts of a tree is made into a table is that a physical or chemical change

Why is photosynthesis so important to plants, and can't animals use it?

One way the government of Kim Jong-il controls the lives of the people who live in North Korea is by a. requiring every citizen to vote. b. controlling information its people receive from the outside world. c. enforcing free trade with other nations.

Give reasons 1) copper utensils and sheets become blackish after some days

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs for? H and? S (for the system).

At 29°C, Kp = 5.3 ✕ 102 atm-2 for the following reaction. N2 (g) + 3 H2 (g) equilibrium reaction arrow 2 NH3 (g) When a certain partial pressure of NH3 (g) is put into an otherwise empty rigid vessel at 29°C, equilibrium is reached when 55.