What are the parts of an atom, and how are they used to determine an atom's mass and identity?

The half life of a certain radioactive element is 800 years. How old is an object if only 12.5% of the radioactive atoms in it remains?

In the following reaction, how many grams of ammonia (NH3) will produce 300 grams of N2? 4NH3 + 6NO → 5N2 + 6H2O The molar mass of ammonia is 17.0337 grams and that of nitrogen is 28.02 grams.

Consider the following reaction: I2O5 (s) + 5 CO (g) → I2 (s) + 5 CO2 (g) Which of the following correctly characterizes this reaction? The oxidation number of iodine in the reactants is + 5. CO is oxidized. I2O5 is the oxidizing agent.

A scientist has tested an experimental drug on laboratory mice and created a model. Which of the following is the next logical step in testing the model?

If the rate of evaporation is equal to the rate of condensation, the system is in a state of dynamic equilibrium, which cannot be disturbed. TRUE FALSE

In the Periodic Table, what is the relationship between two elements that are placed side-by-side in a row? A. The element on the left has one more electron. B. The element on the left has one more proton. C.

What are two traits of pseudoscience

What will happen if an electric current is flowing through a cord and a magnet is brought near the cord?

Lithium has two isotopes. Li-6 and Li-7. Li-6 mass = 6.015121amu Li-7 mass = 7.016003amu Lithium Mass = 6.94049amu What is percent abundance of Li-6? I know that there is an equation: 6.

Why does an apple fall toward the earth, instead of the earth moving toward the apple?