You will be working with calcium chloride; for 5 gm the temperature rose from 20.0 degrees C to 24.0 degrees C; for 10 grams the temperature rose from 19.6 degrees C to 27.6 degrees C; and finally for the 15 grams the temperature rose from 20.3 degrees C to 32.3 degrees C.
show all 3 delta H's that you calculate for your salt.
show your graph (with labels and title) and its calculated slope.

Isec i will do it and them i will let you know

Ithink about 50 % of an original isotope's number of atoms remain

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.

Six base units were recommended: the metre, kilogram,second, ampere, degree kelvin (later renamed kelvin), and candela. in 1960, the 11th  cgpm  named the system the international system of units, abbreviated si from the french name, le système international  d'unités.