What type of changes indicate a physical change?

How many moles are in 4.2 g of H2O

What is the density of an object with mass 150 and volume 30

The amount of I3 - (aq) in a solution can be determined by titration with a solution containing a known concentration of S2O3^2 - (aq) (thiosulfate ion).

The phosphate functional group in the non cyclic adenosine monophosphate molecule contains "acidic hydrogens". Explain what this phrase means.

Do molecules have protons?

Substance which allows energy to pass through it

How are insect wings not likely to be fossilized?

True or False: A Solar eclipse occurs when Earth casts a shadow on the Moon.

Compared to a phosphorus atom, a P3 - ion has (1) more electrons and a larger radius (2) more electrons and a smaller radius (3) fewer electrons and a larger radius (4) fewer electrons and a smaller radius

1. Crystals of ammonium chloride, NH4Cl, seem to disappear when mixed with water. The resulting clear liquid containing ammonium chloride and water is a A) compound. B) new substance. C) homogeneous mixture. D) heterogeneous mixture. 2.