2. Which types of changes observe the law of

conservation of mass?

A. only changes of state

B. only physical changes

C. only chemical changes

D. physical changes and chemical changes

True or false: physical changes occur when enough energy is released or absorbed from a substance

5 examples of each chemical properties, physical properties, chemical changes, and physical changes.

A compound containing nitrogen and oxygen is decomposed in the laboratory and produces 1.78 g of nitrogen and 4.05 g of oxygen, calculate empirical formula

Calculate the number of hydrogen and carbon present in 4g of methane

Object A has a mass of 12 g and a density of 3 g/cm3. Object B has a mass of 12 g and a density of 5 g/cm3. Which object has a greater volume and by how much? Object A, by 2 6 cubic centimeters Object A, by 1.

According to kinetic molecular theory, collisions between gas particles in a sample of an ideal gas (1) increase the energy content of the gas sample (2) produce strong attractive forces between the gas particles (3) result in a net loss of energy

How do transmittance, absorbance, and molar absorptivity differ? Which one is proportional to concentration?

A particular alloy is made of two metals. The density of one of the metals (call it metal A) is 3.0 g/cm3. The density of the other metal (call it metal B) is 5.0 g/cm3. If the density of the alloy is 4.

Who determined that the elements needed to be arranged by atomic number instead of atomic mass?

How many molecules are in 4.50 moles of water