The half life of Sodium-24 is 15 hours. If we have 10 grams of Sodium-24, how much will remain after 15 hours?​

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

The seven sisters, seven stars located more than 400 light-years away in the taurus constellation can be seen here with venus and another constellation, orion. the seven stars stay grouped together but seem to move, like the planet venus. why do stars seem to move like planets in the night sky?