A certain radioactive element has a half-life of one hour. if you start with 1.0 gram of the element at noon, how much of the radioactive element will be left at 2 p. m.? 0.50 grams 0.25 grams 0.125 grams 0.0 grams

Which of the following reactions is an example of a single replacement reaction? Select one: a. Mg + AgNO3 - -> Ag + Mg (NO3) 2 b. Fe + O2 - -> Fe2O3 c. C6H12O6 + O2 - -> CO2 + H2O d. H2O - -> H2 + O2

How to prove that NaCl is homogeneous mixture.

An occuled front moves over farmland that has been experiencing drought conditions. What change in weather likely bring? A. more dry air and snunny skys B. violent, short-lived thunderstorms C. an extented period of rain D. gray skies, but no rain

What is the correct name for Au3N?

What is a disadvantage of using a space-filling model to show a chemical compound?

How much energy, in joules, is released when 17 kilograms of granite is cooled from 45 C to 21 C?

Is feeling warmth from a fireplace convection, radiation, or conduction?

Which part of Dalton's atomic theory was disproved by Thomson's experiment? O Atoms cannot be created, destroyed, or divided into smaller particles. O Chemical reactions occur when atoms combine, separate, or rearrange.

Of the following, which is most likely to result after a farmer sprays his crops with pesticides? A. The crops die. B. The insect population increases. C. The soil dries up and blows away. D. A neighbor's well tests positive for pesticides.

How many liters does the following number of atoms of helium take up? 9.42x10^22 atoms He