What positive impact are used for making a basketball

The chart shows the bid provided by four contractors to complete a job. which contractor is the most cost-effective?

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

In the following table, all the columns for the element calcium are filled out correctly. element electron structure of atom electron structure of ion net ionic charge calcium 1s22s22p63s23p64s2 1s32s22p63s23p64s1 +1 true false