Give the ground state electron configuration for Pb. a. [Xe]6s25d106p2
b. [Xe]6s26p2
c. [Xe]6s25f146d106p2
d. [Xe]6s24f145d106s26p2
e. [Xe]6s24f145d106p2

Identify the electromagnets with poles that are reversed from the electromagnet shown above

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Which statement characterizes synthetic polymers? a. they come from animals and plants. b. they are found in nature. c. they are made in a lab. d. they are components of starch.