2 Flashcards
What is a solid?
Particles are densely packed, vibrate in a fixed position, cannot be compressed, and have a fixed volume and shape.
Solids maintain their shape and volume regardless of the container.
What characterizes a liquid?
Particles can slide past each other, vibrate in an unfixed position, are difficult to compress, and have an unfixed volume and shape.
Liquids take the shape of their container but have a definite volume.
What defines a gas?
Particles bounce and collide, vibrate very fast in an unfixed position, are easily compressed, and have an unfixed volume and shape.
Gases expand to fill their container and have neither fixed volume nor shape.
What is an atom?
The building block of matter.
Atoms consist of protons, neutrons, and electrons.
What are chemical elements?
Pure substances made up of one type of atom.
The periodic table contains over 100 elements.
What are compounds?
Substances formed when two or more different types of atoms chemically combine.
Example: H2O is a compound.
What is a mixture?
Contains several different atoms blended together.
Examples include air and salt water.
What is the composition of air?
78% N2, 21% O2, 1% Ar, 0.04% CO2.
Air is a homogeneous mixture.
Define a heterogeneous mixture.
Composition is not uniform throughout the mixture.
Example: Vegetable soup, where different spoonfuls contain varying amounts of veggies.
Define a homogeneous mixture.
Composition is uniform throughout the mixture.
Example: Vinegar, where each spoonful contains the same components.
What are molecules?
Formed when two or more atoms connect to each other via their electrons bonding.
Examples include H2O (water) and H2 (hydrogen).
