Aradioactive isotope has a half-life of ten days. how much of a 100-gram sample will be left after 20 days? a) 12.5 grams b) 25.0 grams c) 50.0 grams d) 100.0 grams

What type of nuclear decay causes the atomic number of an element to increase by 1?

Ineed asap! list 3 examples in which friction us or makes things easier in our daily life. explain the effect of friction for each. *make sure you explain the effect of friction for each example! *

Standing side by side ,you and a friend step off a bridge at different times and fall for 1.6s to the water below. your friend goes first, and you follow after he has dropped a distance of 2.0m. when your friend hits the water, is the seperation between the two of you 2.0m or more than 2.0m? verify your answer with a calculation.