Unit 1 Flashcards
What is Chemistry?
It’s the study of matter; matter is anything that has mass and volume
What is a chemical change?
One material is changed to form another with different properties. One or more substances are formed.
What is a Physical change?
The physical properties of a substance include such characteristics as shape (volume and size), color, texture, flexibility, density, and mass are changed.
What is a Pure Substance?
Only made of one type of particles.
What is a mixture?
One or more mixture of pure substance.
What is an Element?
Can not be broken down into simpler substances.
What is a compound?
two or more elements that combine chemically.
What is a heterogeneous?
two or more phases of mixture is visible.
What is a homogeneous?
Only one phase of mixtures is visible.
Quantitative observation?
determination of amount; can be measured.
Qualitative observation?
Involves descriptive properties that can not be measured.
An inference?
Is a conclusion reached on the basis of evidence and reasoning.
An observation
Observations can be made only with the five senses.
What did Dalton discover?
He proposed that atoms are solid sphere.
What did Thomson discover?
He discovered electrons.
