D the nucleus 6
In order to perform an experiment, a chemist needs an element that has similar
properties to potassium (K) but a lower atomic mass. Which element should the
chemist select for the experiment?
F Rubidium (RD)
G
Sodium (Na)
H Magnesium (Mg)
3
Calcium (Ca)

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Light waves are as they pass through the

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt