2.1 Matter Flashcards
What do elements consist of?
1 atom
What do compounds consist of?
Molecules (groups of elements)
What does an atom have?
Nucleus, proton and neutron.
What does the neucleus consist of?
Protons and neutrons.
What is important about protons and neutrons despite one being negative and one positive?
The have the same mass.
What is the atomic number?
Number of protons in the nucleus and is how an atom is identified.
What is the mass number?
The number of protons and neutrons in the nucleus.
Which way are orbiting electrons charged?
Negatively.
What is the mass of an electron vs a proton?
1/1845 however they hold the same electrical charge.
How does an atom become neutral?
Having the same number of electrons and protons.
What is the simplest atom?
Hydrogen because it has one proton and one electron.
How are the layers/shells of electrons labelled?
Alphabetically, starting with K at the closest shell to the nucleus.
How is the maximum number of electrons per shell governed?
Using the formula 2n² where n is the numerical number of the shell.
What is the valence electron?
The outermost electron in orbit.
When atoms are close together what are the forces between them?
Electromagnetic in nature.
What is the result of the electromagnetic force between atoms?
When they are a certain distance apart there is zero force, when they are closer they repel, when they are further away they attract.
In a solid substance what do the molecules do?
Vibrate about their zero positions, alternately attracting and repelling.
What structure do all true solids have?
Chrystal-line, where the atoms are arranged in a lattice.
In a liquid what do the molecules do?
They vibrate similar to a solid however they can freely move among one another.
In a gas substance what do the molecules do?
They are much further apart and move at high velocities colliding with one another.
Why is a gas completely free to expand to the container it is in?
Because the molecules are so far apart that there are no intermolecular forces to either repel or attract.
The word heat is the name given to energy in the process of what?
Energy transfer from one body to another as a result of the temp difference.
What happens to heat once it has been transferred to a body or substance?
It ceases to be heat and instead becomes internal molecular energy.
How does a solid become liquid?
The molecules gain energy vibrate over bigger distances and can move freely becoming liquid state.