2.1 - Matter Flashcards
What are atoms made up from?
Subatomic particles; protons, neutrons and electrons
What makes up the nucleus of an atom?
Protons and Neutrons
What do electrons orbit around a nucleus of an atom in?
Shells
Electrons in the closest shell to the nucleus have the _____ amount of energy whereas the electrons in the outer most shell have the _____ amount of energy.
Electrons in the closest shell to the nucleus have the LEAST amount of energy whereas the electrons in the outer most shell have the HIGHEST amount of energy.
What does Subatomic mean?
‘Smaller than an atom’
How small are electrons in comparison to protons and neutrons?
Nearly 2000 times smaller
What is an elements atomic number?
It’s number of protons. It’s used to arrange the elements in the periodic table.
Who published the first widely recognised periodic table of elements?
Dmitri Mendeleev in 1869
They were arranged in order of the properties of the then-known elements.
What group number are halogens?
Group 17
What group number are noble gasses?
Group 18
What does the group number (vertical column) signify?
The number of electrons in the outer shell.
What is the difference between a mixture and a compound?
A mixture isn’t chemically bonded together meaning it can be easily divisible back to original elements by physical means, but a compound is chemically bonded together meaning it can only be divisible back to it’s elements by chemical processes.
What is Chemical Synthesis?
The name given to the purposeful execution of chemical reactions to obtain a compound.
What is the process of a chemical reaction to break down (splitting) a compound into it’s constituent elements called?
Chemical Analysis,
Decomposition, or;
Breakdown
How many elements are known today?
There are at least 118 elements in our known universe.
What is a molecule?
A combination of two or more atoms connected in a fixed ratio that act as a single unit. They have been chemically bonded with each other.
What does Diatomic and Triatomic mean?
Diatomic - a molecule made up of two of the same atoms bonded together (O2)
Triatomic - a molecule made up of three of the same atoms bonded together (O3)
What are the reactants in a chemical reaction?
The substances initially involved in a chemical reaction
What is added to a chemical reaction (apart from heat) that will increase the rate of the reaction?
A catalyst; an additional chemical added to increase the rate of the reaction
What is an inhibitor?
Opposite of a catalyst; also known as “negative catalysts” because they decrease reaction rates
What is the atomic number also known as?
The proton number (Z)