a toy plane weighs 500g. when placed in water, it changes the water level from 250ml to 300ml. what is the density?

What percentage of a radioactive substance remains after two half-lives?

What are some non examples of biodiversity

The time required for a radioactive mass to reduce by a factor of 2 is called:

What is a substance used to increase the rate of a chemical reaction but it itself is not used up in the process?

Which of the following quantities is the largest? 0.00001101 kg 0.001011 g 0.000001101 kg 0.0001011 g

What evidence of a chemical reaction might you see in dropping an Alka-Seltzer tablet into a glass of water?

State hess's law. how is it used

When the name of a molecule ends in - ose, the molecule is a

How many moles are in. 12 grams of gold.

When lithium reacts with bromine to form the compound LiBr, each lithium atom: (1) gains one electron and becomes a negativelycharged ion (2) gains three electrons and becomes a negativelycharged ion (3) loses one electron and becomes a