Basics Flashcards
(15 cards)
What are atoms
An atom is a particle of matter that uniquely defines a chemical element
How many atoms are an element made of
One
What are atoms made of
large, positively charged protons and neutral neutrons found in the nucleus surrounded by very small negatively charged electrons located in a cloud
Name the first 20 elements of the periodic table
Hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminium, silicon, phosphorus, sulphur, chlorine, argon, potassium, calcium
What is an atomic number
charge number of an atomic nucleus
What is a mass number
the total number of protons and neutrons in an atomic nucleus
in a neutral atom, how many protons and electrons
protons = electrons
What are isotopes
different versions of an atom - same atomic number and position in the periodic table and chemical properties but with different atomic masses and physical properties
protons and electrons in isotopes
protons = electrons
What is an element
- The simplest kind of substance that cannot be broken down into anything simpler
- All its atoms have the same number of protons
What is a compound
A substance made from two or more different elements chemically combined together.
electron configuration
2, 8, 8, 2
how are atoms stable
full valency/outer shell
Physical changes
- Can easily be undone
- No new material is formed
- Change in state
Chemical change
- Cannot easily be undone
- New materials formed that are different to the starting materials
- Colour change
- Bubbles given off
- Temperature change or light given off
