25 pts 2. The data in the table show the amount of a 500 g sample of sodium-24 over time.
Make a graph of the data (remember to label all axes and title the graph).
What is the half-life of sodium-24? Explain how you determined your answer.
Sodium-24 decays by beta emission. Write a nuclear equation that shows the decay of sodium-24 and
its products

Zoe is investigating the composition of substance a, an unknown substance. using chemical processes, she analyzes substance a and determines it is composed of sodium, oxygen, and hydrogen atoms in a ratio of 1 : 1 : 1. what is substance a? a. a compound b. an element c. a heterogeneous mixture d. a homogeneous mixture

In 2002, the rare earth elements mine in mountain pass, california was closed because

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o