3. Atoms can be considered the basic building blocks
of matter
8
Atom X has 9 protons, 10 neutrons
and 9 electrons
Atom Y has 9 protons, 9 neutrons
and 9 electrons
Which of the following statements best describes
how Atom X and Atom Y are related?
A X and Y are isotopes of the same element,
B
X is an ion and Y is a neutral atom.
X and Y are different elements.
D. X is neon and Y is fluorine.

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Two people each hold the end of a rope and create waves by moving their arms up and down. this wave is best classified as a transverse wave because a) both the rope particles and the wave are moving in the same direction. b) the wave is moving up and down as the particles of the rope move horizontally. c) the wave is moving horizontally as the particles of the rope move up and down. eliminate d) the wave is moving in a parallel direction with the motion of the person's arms.

You are attempting to recrystallize a crude product mixture. you add the appropriate amount of hot solvent and are allowing the solution to slowly cool to room temperature. however, at room temperature no crystals have appeared, which of the following methods should be used to induce crystallization? choose all correct answers. a) place the flask in an ice bath. b) swirl the contents of the flask. c) add a small seed crystal of the desired product. d) scratch the inside of the glassware using a stir rod. it can be multiple choices