20) After 8 hours, half of a 16-gram sample of a radioactive element remains. Find the constant k for this element for t hours, then use y=ne^-kt to write the equation for modeling it’s exponential decay - please help me

Ibeg you to me 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

If a line is defined by the equation y = 5x + 2, what is the slope?

Answer asap and if you do you will get brainliest. catherine buys a gallon of ice cream from the store. after taking it home, she eats a fifth of a gallon of ice cream. her sister eats some of the ice cream as well. if two-thirds of the original amount of ice cream is left, then what fraction of a gallon of ice cream did her sister eat?