# Chemistry Chapter 1-5 Vocab

## 97 terms

### Weight

a measure of the gravitational attraction for an object

### Experiments

controlled observations for testing a hypothesis

### Matter

anything that has mass and takes up space

### Technology

The application of science to the solution of everyday needs

### Qualitative Data

descriptive, non-numeric information

### Dependant variable

the variable that changes as a result of your planned changes

### Substance

matter with a definite and uniform composition

### Systematic Approach

an organized approach to finding the solution for a problem

### Mass

a measure of the amount of matter in an object

### Quantitative Data

numerical information

### Pure Research

research for the sake of gaining knowledge alone

### Scientific Law

a description of natural behavior
a relationship supported by many observations

### Control

a standard for comparison

### Conclusion

a judgement based on observed information

### Model

a visual, verbal or mathematical explanation of experimental data

### Hypothesis

a tentative explanation

### Scientific Method

a systematic approach used in the study of science

### Observation

the act of gaining information

### Independent Variable

the variable you plan to change

### Applied Research

research for the sake of solving everyday problems

### Scientific Notation

a method of expressing numbers in the form of 2.3 X 10^8

### Significant Figure

all the known digits in a measurement plus one estimated digit

### Density

mass per unit volume

### Experiment

a set of controlled observations used to test a hypothesis

### Base Unit

a defined unit based on an object or event in the natural world

### Error

the difference between an experimental value and the accepted value

### Conversion Factor

a ratio of equivalent values having different units

### Accuracy

how close a measurement is to an accepted value

### Graph

a visual display of data

### Derived Unit

a unit defined by the combination of base units

### Precision

how close a group of measurements are to each other

### Percent Error

measure of error as a percent of the accepted value

### Liter

a derived unit used for measuring liquid volumes

### Dimensional Analysis

a systematic process of problem solving using conversion factors to convert between units

### Chromatography

a separation technique based on how one material travels across the surface of another material

### Liquid

state of matter with a definite volume and takes the shape of the container

### Homogenous Mixture

a mixture with uniform characteristics

### Phase Change

the transition of matter from one state to another

### Element

a pure substance that cannot be broken down by chemical or physical processes

### Solid

a state of matter that has a definite shape and a definite volume

### Physical Change

a change that does not change the identity of the substance

### Intensive Property

a physical property not dependent upon the amount of the material

### Proportion

a numerical relation of one part to another part or to the whole

### Chemical Change

a change in which one or more new substances are formed

### Physical Property

a characteristic of a material that does not involve changing the identity of the material

### Distillation

a separation technique based on differences in boiling points

### Heterogeneous Mixture

a mixture that does not have uniform composition

### Solution

a homogenous mixture

### Compound

a chemical combination of two or more elements

### Solute

the part of a solution that is dissolved

### Mixture

a physical combination of two or more substances

### Crystallization

a separation technique that produces solid particles from a solution

### Chemical Property

a characteristic describing how a substance will react to form new substances

### Percent by Mass

the ratio of the mass of an element to the mass of the compound expressed as a percent

### Extensive Property

a physical property dependent upon the amount of the material

### Solvent

the part of a solution that does the dissolving

### Vapor

the gas form of a substance normally a liquid or solid at room temperature

### States of Matter

the physical forms in which all matter naturally exists

### Filtration

a separation technique that uses a porous barrier to separate solids from liquids

### Sublimation

changing from a solid to a gas directly

### Gas

state of matter with no definite shape and no definite volume

### Periodic Table

a chart that organizes all known elements into a grid of horizontal rows and vertical columns

a helium nucleus

### Element

a pure substance that cannot be broken down into simpler substances by physical or chemical means

### Cathode Ray

a stream of charged particles

### Gamma Ray

a very high energy form of radioactive decay

### Beta Particle

an electron originating from the nucleus

### Atom

the smallest particle of an element that retains the properties of that element

### Nucleus

the positively charged dense center of an atom

### Neutron

a neutral particle in the nucleus of an atom

### Atomic Mass Unit

1/12 the mass of one atom of carbon-12

### Theory

an explanation of natural behavior, supported by many experiments

### Atomic Number

the number indicating the number of protons in an atom and the identity of the element

### Isotope

one or more atoms containing the same number of protons but a different number of neutrons

### Electron

a negatively charged particle that is part of all forms of matter

### Model

a visual, verbal, and/or mathematical explanation of data collected from many experiments

### Proton

a positively charged particle in the nucleus of an atom

### Mass Number

a number representing the number of protons and neutrons in an atom

### Electron dot Structure

an element's symbol surrounded by dots representing valence electrons

### Wavelength

the shortest distance between equivalent points on a wave

### Energy Sublevel

the energy levels contained within a principal energy level

### Principle Quantum Number

assigned to represent the relative energies of the atomic orbitals

### Amplitude

the height of a wave from origin to crest

### Photon

a massless particle of electromagnetic radiation

### Electron

a negatively charged particle that travels in the empty space surrounding the nucleus of an atom

### Quantum Number

a number assigned to each orbit of an atom. One of a set of four numbers describing an electron

### Planck's Constant

6.626 X 10^-34 j/Hz

### Frequency

the number of waves that passes a given point per second

### Atom

the smallest particle of an element that retains the properties of the element

### Principal Energy Level

the major energy levels of an atom

a form of energy with wave properties that can travel through empty space

### Valence Electrons

the electrons in an atom's outermost orbitals

### Electron Configuration

the arrangement of electrons in an atom

### Quantum

the minimum amount of energy that can be gained or lost by an atom

### Atomic Orbital

a region around the nucleus that describes an electron's probable location

-energy level
-sublevel
-orientation
-electron spin