4. You are asked to explain physical and chemical changes using a newspaper How will you demonstrate the two types of changes?
5. A brick is broken into several pieces. What type of change is involved? Will the mass and
volume change?

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.