A atom has 20 electrons, 21 neutrons, and 20 protons. What is the atomic mass of the atom?

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

During chemistry class, carl performed several lab tests on two white solids. the results of three tests are seen in the data table. based on this data, carl has concluded that substance b must have bonds.

There is a single path for electrons. the current decreases when additional resistors are added. the current will be the same in each resistor. these statements best describe a(n) circuit.