WGU D425 Intro to Chemistry Questions and Answers | Complete Study Guide

WGU D425 Intro to Chemistry Questions
and Answers | Complete Study Guide
• Solid . Answer: definite shape & volume

• Liquid . Answer: definite volume, takes shape of container

• Gas . Answer: no definite shape or volume

• Plasma . Answer: super hot ionized gas

• Intensive Property . Answer: doesn't depend on amount (density, color, melting point)

• Extensive Property . Answer: depends on amount (mass, volume)

• Physical Change . Answer: shape/phase changes, no new substance

• Chemical Change . Answer: makes a new substance

• Homogeneous Mixture . Answer: looks the same everywhere (lemonade)

• Heterogeneous Mixture . Answer: can see different parts (salad)

• Compound . Answer: 2+ elements chemically combined

• Element . Answer: 1 type of atom

• Atomic Number . Answer: # of protons

• Mass Number . Answer: protons + neutrons

• Isotopes . Answer: same protons, different neutrons

• Neutrons Equation . Answer: Neutrons = Mass number − Atomic number

• Atomic Mass Unit (amu) . Answer: Proton ≈ 1 amu, Neutron ≈ 1 amu, Electron ≈
0.00055 amu

• Average Atomic Mass . Answer: Avg. mass = ∑(fractional abundance × isotope mass)

• Synthesis Reaction . Answer: A + B → AB

• Decomposition Reaction . Answer: AB → A + B

• Single Replacement Reaction . Answer: A + BC → AC + B