What are the four ways to tell if a chemical change has occurred?

What physically breaks hydrogen bonds between water molecules as ice melts? what physically breaks hydrogen bonds between water molecules as ice melts?

Gold has a density of 19.3g/cm3. What is the mass, in grams, of a sample of gold with a volume of 47.2 cm3?

Hg2I2 (s) ⇄ Hg2 2 + (aq) + 2 I - (aq) Ksp = [Hg2 2+][I-]^2 A saturated solution of Hg2I2 is at equilibrium at 25°C as represented by the equation above. If [I-] = 4.

A substance decays so that the amount a of the substance left after t years is given by: a = a 0 · (0.9) t, where a 0 is the original amount of the substance.

Aluminum + lead (ii) >aluminum nitrate + lead balanced equation

Two metals with equal mass and different heat capacities are subject to the same amount of heat; which undergoes the smallest change? a) The metal with the higher heat capacity. b) The metal with the lower heat capacity.

What is the first man made organic compound synthesized in laboratory?

Express (3 x 104) (4 x 1023) in scientific notation

Use Dimensional Analysis: convert: 0.36km/sec to m/min 2.6L to cm^3 9cm to mm 7.6mm^3 to cm^3

Something occurs when a liquid changes to a gas below its surface as well as on the surface