Atomic Structure part 2 Flashcards
Ions, atoms and isotopes
What is an Ion?
An atom that gains or loses electrons to become charged. When an atom loses electrons, it becomes positive. When an atom gains electrons, it becomes negative.
What is an isotope?
Atoms of the same element with different numbers of neutrons. They differ to their regular element by Mass Number.
Describe the properties of isotopes compared to a regular element (2 things)
They have identical chemical properties but their physical properties such as density can differ.
How do you know how many electrons there are in an element?
The number of electrons in a neutral atom equals the number of protons, which is given by the atomic number.
How do you know how many neutrons are in an element?
The mass number is the total number of protons and neutrons in the atom. Mass number - Atomic number = Number of neutrons.
How do you work out the amount of electrons in an ion?
Find its atomic number, then plus or minus the number of the charge. If it is Na+ it has lost one electron, so it is atomic number - 1. If it is Na3- it has gained three electrons, so it is atomic number + 3.
What makes a stable element?
Having the most complete (full) outermost electron shell. (Because the number of electrons in the outermost shell determines how the element reacts).
Which is on top of the element symbol- Mass number or atomic number?
Mass number
What does a chemical property of an element depend on?
How many electrons it has.
How many electrons can be held in the second (closest) electron shell?
Up to 8, in 4 pairs of 2
How many electrons can be held in the lowest/closest electron shell to the nucleus?
2
What is atomic radius?
The atomic radius is the distance from the center of an atom’s nucleus to its outermost electrons. It gives an idea of how large an atom is.
How many electrons can be held after the second electron shells ( third and beyond)?
Also 8 in 4 pairs of 2!
How do we write the electronic structure?
Instead of drawing the electrons on the rings as ‘X’s we count them by shell, separated by commas. For example: Boron has 2 in its first shell, then 3 in it’s second so is written as 2,3.
How do metals react with to nonmetals?
Metals react by losing electrons. Non metals react with metals by gaining electrons.
