Chemistry Unit 1 test Flashcards
What is an allotrope
One or more forms of an element that can exist in the same physical state
What is a physical change
When the identity of a substance says the same but something physical of the object may change
What is a chemical change
When the identities of a substance change & a new substance forms
Equation for density
density = m/v
Equation for Volume
Volume = m/d
Equation for mass
Mass = d/v
What is a pure substance?
A pure substance is a sample of matter that has definitie chemical and physical properties
What is a heterogenous mixture
They have visually distinguishable components, not mixed
What is a homogenous mixture?
They have a uniform throughout look
How are the particles in a solid
Packed together and unable to move
How are the particles in a liquid
In a liquid the molecules are able to move around one another but still relatively close together
How are the particles in a gas
In a gas the molecules are spread out & move freely
Examples of allotropes?
O2 & O3 are allotropes for Oxygen
Example of a physical change?
Crushing a rock, dissolving sugar, changing location, arrangement, or speed
Example of chemical changes?
mercury (II) oxide (arrow) mercury + oxygen
baking a cake, burning wood
