Chemestry Flashcards
How are elements classified?
Based on the atomic number of their atoms
Elements are listed in order of…
Their atomic number
How many columns are there?
18
What are the two types of properties?
Observable and measurable
Define observable properties
Properties that you can touch, feel, taste, smell, and see.
Define measurable properties
Properties that include numbers and measurement
Define pure substance
Only 1 particle, but can have multiple atoms. They only have one set if properties.
What are the two sub categories of pure substances
Elements and compounds
Define elements
Made of only one type of atom and can’t be broken down into simpler subtenses by chemical reactions.
Define compounds
Made of two or more elements that have been chemically combined into one.
Define a particle
two or more atoms chemically connected together
Define molecule
a particle made of two or more atoms chemically connected together
Compounds are..
pure substances made of two or more elements that have been chemically combined into molecules
Hydrogen and oxygen are ________ gasses
Flammable
Define mixture
A (non chemical) combination of two or more pure substances
Define mechanical mixture
A rough mixture where the individual components can be distinguished by eye
Define suspension
A cloudy mixture in which clumps of a solid or droplets of a liquid are scattered throughout a liquid or gas
define solution
A uniform mixture where any given part of it contains the same ratio of ingredients
Name three properties of a physical change.
- Reversible
- no chemicals are changed
- The substance doesn’t change
Name three properties of a chemical change.
- often irreversible
- Chemical bonds have changed
- The substance changes into something else
