The density of Earth is about 3.5 g/cm². Earth has a radius of 7000 miles. What is its mass? (volume of a sphere = 4pir)

Which is true of transition metals when moving from left to right on the periodic table? the d sublevels are not filled across the period. the cation radii become larger across the period. atomic radii increase slightly and then start to decrease. atomic radii decrease slightly and then start to increase. o

Complete the sentence. the lower the hydrogen ion concentration, the the ph. higher lower closer to 7 closer to 0

Describe the difference between a. a hypothesis and a theory and b. an observation and an experiment.