Is silver tarnishing a physical change or a chemical change?

Complete the table for ion charge based upon their losing or gaining electrons in the outer shell. (use the periodic table as necessary.) group most likely ionic charge # of valence electrons i +1 ii +2 iii +3 iv +4 or -4 v -3 vi -2 vii -1 viii 0

Sarah wants to know where in her garden chamomile would grow the best. she thinks chamomile will grow best in the corner of the garden that gets the most sunlight. to test her hypothesis, she decides to plant several groups of chamomile in her garden as an experiment. which of the following variables will sarah need to measure to know which group of plants grew best? a. the location of the plants b. the type of plants c. the height of the plants d. the amount of water she gives the plants

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)