In each case are the 2 events dependent or independent toss a dime and then toss a quarter pick a card from a deck of cards keep the card and pick another one

1. independent 2. dependent toss a dime and then toss a quarter * Ask yourself, "Does the 1st event have any effect on the results of the 2nd event?" And in this case, the answer is no. No matter what result happened for the dime flip, it won't affect the quarter flip. So these events are independent. pick a card from a deck of cards keep the card and pick another one * Ask yourself the same question. The 1st card is one of any of the 52 cards in the deck, while the 2nd card is from the remaining 51 cards. So the 1st event does affect the 2nd event. Therefore they're dependent.

Aand b are correctly balanced reactions. they have the same number of atoms in both sides of the reaction

It will never be positive always negative