ASVAB General Science Practice Test 453440

Questions 5
Topics Acidity, Periods, Phase Transition, Solid

Study Guide

Acidity

An acid is a substance that gives up positively charged hydrogen ions (H+) when dissolved in water. A base (alkaline) gives up negatively charged hydroxide ions (OH-) when dissolved in water. pH is a scale that measures of how basic or acidic a solution is. Numbered from 0 to 14, solutions with a pH of 7 are neutral, less than 7 are acidic, more than 7 are alkaline.

Periods

The rows of the Periodic Table are called periods and contain elements that have the same number of electron shells ordered from lower to higher atomic number.

Phase Transition

A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.

Solid

An element in a solid state has atoms or molecules that are constricted and do not move freely. Solids maintain a constant volume and shape and exist at a lower temperature than liquids or gases.