Periodic Table and atomic structue Flashcards
(57 cards)
Define a pure substance
A substance that cannot be seperated into a different substance by physical means
Define mixture
A combination of two or more pure sustances that can be seperated eaisly by physical means - they are not chemically bonded
Define an atom
An atom is the smallest unit of an element, consisting of a dense nucleus of protons and neutrons surrounded by a cloud of electrons.
What is a molecule
2 or more atoms held togethro by chemical bonds, can contain dif elements eg h2o
What is a compund
2 dif elements joined togethor by chemical bonds
Whtas an element
An element is a pure substance made up of only one type of atom
Where are the protons found
In the nucleus and they are positively charged
Where are the newtrons found
in the nuclues and the are neutral
Where are the electrons found
in the shells and they are negatively charged
Opposites …. Likes
Opposites attract like repel
What is the structure of an electron shell diagram
Protons and Newtrons in the nuclues, then elcetrons on the shells,
2 than 8.
How do we use the periodic table to find the amount of subnatomic particles in a atom?
You minus the mass number - hte atomic number to find the number of electrons
The atomic number AKA the one at the bottom is the number of protons and it never ever changes.
What is the chemical symbol
The letter infront
Explain why internationally used symbolsa are used for common elements
Internatiinally recognized symblos are used for elements to create a universally understood language in science, this ensures clear comminucation and chamical formulas and experiments.
Which area of the table is metal
everywhere but top left
What area of the periodic table is non metal
the top left corner
What is teh democritus model
A solid ball model as its none as
Suggests that all atoms are small hard invisble idestructable particles made of a single material formed into different shapes and sizes
What is teh plum pudding model/tehroy
JJ tomphson suggests that atoms mostly consisted of positively charged particles and with negatively charged particles located throughout the positive material
Poistive dough, negative plums
What did Ernest Rutherford suggest?
He did a goldfoil experiment and suggested that an atom contains a small core aka a nucleuas that contains the most mass this nucleus is made up of protons which have a positive charge and that the protons are surrounded by negatively charged electrons but most of the atom is actually empty space
What is the gold foil experiment
Rutherford and his team shot alpha particels (positively chraged) at a strip of gold foil and expected them to go straight through it though this did not happen as some of them we’re replled and sent it flying directions as they hit the positive prontons in the nucleus
What is the planetary model
Neils Bohr basically suggested that electrons travel around the nucleus of an atom in orbits or paths, and aditionally can jump from path to path depending on thier energy level.
Can electrons jump from shelf to shelf?
Erwin Schrodinger further explained the nature of electrons in an atom by stating that the exact location of an electron cannot be stated;
therefore, it is more accurate to view the electrons in regions called electron clouds;
electron clouds are places where the electrons are likely to be found
What did James Chadwich
Define a chemical change
A chemical change is a change in which a new substance is formed and cannot be reversed by phsical means. (easily)
