Which of the following elements is the most reactive? potassium lithium sodium rubidium

If 10.0 ml of the solution on the right are withdrawn from the 100 ml beaker and diluted again in a similar manner, what is the new concentration? m nacl

If the density of water is 1.0 g/cm3, which of these materials would float in water, based on their densities? check all that apply. aluminum cork iron lead wax

Which of the following is an indication that a substance has undergone a chemical change? a. no new product has been formed. b. the color of the substance has not changed. c. the original constitute has not changed. d. the molecular structure has changed.