Chemical World Flashcards
Matter….(3 points)?
- occupies space
- has mass
- mainly composed of atoms
3 physical states of matter?
- gas
- liquid
- solid
Energy….(4 points)?
- does not take up space
- has no mass
- can be measured by its effect on matter ‘capacity to do work or put matter into motion’
- comes in a range of forms
How can you transform matter from one state to another?
By adding or subtracting heat
What are elements?
Substances made up of atoms which cannot be readily broken down into simpler substances eg. Oxygen, hydrogen, nitrogen, carbon
What are molecules?
Two or more atoms joined together
What is a chemical compound?
Is a molecule made of atoms from different elements eg. Water, carbon dioxide, sodium chloride
How many elements in the periodic table?
92
Atoms are made of?
- protons (+ve charge)
- neutrons (neutral, keep a nucleus stable when multiple protons)
- electrons (-ve charge)
What is in the nucleus?
Protons and neutrons
Where are the electrons?
Arranged in shells around the nucleus
What is the atomic mass?
The number of protons in an atom
What is the atomic weight?
Total number of protons and neutrons
What is an isotope?
Variations in the number of neutrons held in the nucleus of an atom
Isotopes can be…(3 points)?
- stable (effectively last forever)
- unstable Or radioactive (break down at varying rates)
What is an ion?
An atom or compound that has gained or lost electrons to give it an overall positive or negative charge
What is a cation?
An atom that loses an electron to become positively charged, fewer electrons than protons