According to Bohr's model of the atom, electrons can be found a. anywhere in the atom
b. in the nucleus
c. anywhere in the atom except for the nucleus
d. on orbits or energy levels around the nucleus

When the chemicals iron sulfide (fes) and hydrochloric acid (hcl) are combined, bubbles appear from the mixture. 1. does the appearance of bubbles indicate a physical or chemical change? 2. why do the bubbles indicate this change? 3. what property is this?

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.

Match the formula for the following compound:   magnesium sulfate heptahydratemgs·7h2omg2so4·7h2omg(so4)2·7h2omgso4·7h2o