What does mould mean?

Is the following chemical equation balanced? 2Na + 2H2O ⇒ 2NaOH + H2 yes no

True or False? You should change the subscripts to balance chemical equations.

How many grams are in 6.53 moles of Pb

According to the graph, which activity has used the largest amount of water over the past twenty years?

What observation led Marie Curie to discover radium and polonium?

The electron configuration 1s22s22p63s23p6 represents which noble gas?

What are some disadvantages of incinerators?

What mass of potassium chlorate would contain 40grams of oxygen?

Identical forces act for the same length of time on two different masses. The change in momentum of the smaller mass is A) smaller than the change in momentum of the larger mass, but not zero. B) zero.

How many nuclei of 238 92 U 92 238 U remain in a rock if the activity registers 290 decays per second? (Note that the half life of Uranium-238 is 4.468x109 years)