A sample of a certain isotope has an initial activity of 40,000 cpm. After 24.8 days, the activity is 2500 cpm. What is the half life of the isotope?

Explain what happens at the saturation point when adding salt to water at room temperature.

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals

C=59(f−32)the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true? a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of 59 degree celsius.a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit.a temperature increase of 59 degree fahrenheit is equivalent to a temperature increase of 1 degree celsius.a) i onlyb) ii onlyc) iii onlyd) i and ii only