True or false exosphere is the least dense

4. Which of the following elements is stable? A. Fluorine, atomic number 9 B. Carbon, atomic number 6 C. Boron, atomic number 5 D. Neon, atomic number 10

Tightly bound group of atoms that behaves as a unit and carries a net charge is what?

Which of the statements was not a part of Dalton's original atomic theory? a. Atoms of the same element have the same size, mass, and structure. b. Atoms cannot be created or destroyed in a chemical reaction. c.

What is half of 1 and 1/3 cups of semisweet chocolate?

Which of the following materials is a good conductor of electric current? a rubber tire a light bulb filament a glass pane a silver spoon

Can someone reword this? A magnetic substance has magnetic fields. These fields start at the North Pole wrap around the magnet, and terminate at the south pole of the magnet. All magnetic substances have north and south poles

Which of these is produced when fossil fuels are burned? A) oxygen Eliminate B) nitrogen C) hydrogen D) carbon dioxide

Predict the sign of ΔSsys for each of the following processes. Which are positive? (a) Gasoline vapors mix with air in a car engine. (b) Hot air expands. (c) Humidity condenses in cold air.

A system consists of two components, each of which must activate if the system is to activate. One component has a reliability of. 99. The other has a reliability of. 95. The components are independent of one another with respect to reliability.

Which of the following energy level changes for an electron is most energetic? 3 → 2 5 → 2 4 → 2