In a molecule of calcium sulfide, calcium has two valence electron bonds, and a sulfur atom has six valence electrons. how many lone pairs of electrons are present in the lewis structure of calcium sulfide?

What is the ph of a solution with a 1.50 × 10−9 m hydroxide ion concentration?

Is a pencil falling to the floor anon contact force, a force, or a contact force

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.