C1.1 Fundamental ideas about chemistry Flashcards
What is an element
A substance made up of 1 sort of atom
How many different elements are there?
over 100
Where are the elements shown?
in the periodic table
What do groups in the periodic table contain?
elements with similar properties as the elements all have the same number of electrons in their outer shell.
Atoms of each element are represented by a …
chemical symbol
What does ‘O’represent
an atom of Oxygen
What does ‘Na’ represent?
An atom of Sodium
Describe the structure of an atom
small central nucleus, which is made up of protons and neutrons
Around there are electrons in shells
What are the relative electrical charges of protons, electrons and neutrons?
proton +1
Neutron 0
Electron -1
What is the charge of an atom?
Atoms have no overall electric charge
In an atom the number of electrons is equal to..
The number of protons
What is the atomic number?
The number of protons in an atom of an element
What is the mass number?
The sum of the protons and neutrons in an atom
What do electrons occupy?
Shells
What is the maximum number of electrons in the 1st shell?
2
What is the maximum number of electrons in the 2nd and 3rd shells?
8
What are elements in group 0 called?
nobel gases
Why are nobel gases unreactive?
their atoms have stable arrangements in electrons. - full outer shell
Describe covalent bonding
When nonmetals share an electron to fill up its outer shell.
This forms a molecule
Describe ionic bonding
between a metal and nonmetal. metal atom loses an electron to have a full shell, forming a positive ion and the nonmetal gains this electron to have a full outer shell, forming a negative ion. The opposite charges of the ions means that they’re strongly attracted to each other.
Describe the conservation of mass
no atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants.
All substances are made out of…
atoms
Name the two sub-atomic particles in a nucleus of an atom
protons
neutrons
Why is there on overall charge of an atom?
because the number of protons is equal to the number of electrons
Why does aluminium react with iron oxide?
because it is more reactive than iron
aluminium displaces the iron so aluminium oxide is formed
Compounds formed when non-metals react with metals consist of particles called……..
ions
Compounds formed from only non-metals consist of particles called
molecules
