ChemH Unit 1

Classifying matter, particles, vocab, etc

What is Qualitative observation?

Observing an item using your senses (ex. sight, smell)

What is Quantitative observation?

Observing with numbers (measurements, volume)

Define Fact

observations about the world around us

Define hypothesis

A proposed explanation for a phenomenon made as a starting point for further investigation

Define theory

a well substaines explanation acquired through the scientific method. often a prediction with an explanation.

Define law

a statement based on repeated experimental observations that describes a phenomenon in nature

Define science

the process of studying the natural world

What’s the relation between technology and science

Science is the search for scientific knowledge whereas technology is the application of science.

What happens to attractive forces between the particles as they get closer together.

the forces get stronger as the particles are closer together

What measures the average kinetic energy of a substance

its temperature.

Can elements or compounds be decomposed by chemical means

compounds

What is another name for a homogenous mixture?

a solution

define mixture

a combination of two or more substances, identities/properties of the individual substances are retained, and can be separated by physical means

define pure substance

has a fixed composition, composed of just one particle (atom or molecule)

Why can’t elements be broken down?

They are already at the smallest possible unit because they are made up of only one type of atom

Define physical property

characteristics of matter that can be observed or measured without changing the identity of the substance

define extensive

depend on the amount of matter present (mass, volume)

define intensive

does not depend on the amount of matter present (water boiling, density, color)

Define chemical properties

a substances ability to undergo changes that result in a different substance with different properties

define density

a ratio of mass to volume of a substance