C1.7 - R* Ions, atoms and isotopes Flashcards
If an atom gains 1 or more electrons, why does it gain an overall negative charge?
If an atom gains: 1. 1 Or, 2. More electrons, it gains an overall negative charge, because it has more electrons than protons
Ion
An ion is a: 1. Charged atom Or, 2. Group of atoms produced by the loss or gain of electrons
How big is an atom?
An atom is about 1/10th of a billionth of a metre across
Atoms of the same element always have the same number of protons, but what can they have different numbers of?
Atoms of the same element always have the same number of protons, but they can have different numbers of neutrons
Isotopes
Isotopes are different forms of the same element, which have the same number of protons, but a different number of neutrons
What do isotopes have?
Isotopes have:
- The same atomic number
- Different mass numbers
Why is the nucleus sometimes radioactive?
The nucleus is sometimes radioactive, because sometimes extra neutrons make the nucleus unstable
Why aren’t all isotopes radioactive?
All isotopes aren’t radioactive, because they are simply atoms of the same element that have different masses
What do samples of different isotopes of an element have in relation to physical properties?
Samples of different isotopes of an element have different physical properties
What do samples of different isotopes of an element have in relation to chemical properties?
Samples of different isotopes of an element always have the same chemical properties
Why is the electronic structure the same for all isotopes of an element?
The electronic structure is the same for all isotopes of an element, because their atoms will have the same number of:
- Protons
- Therefore electrons
The 1st isotope of hydrogen
The 1st isotope of hydrogen is Hydrogen (hydrogen-1)
The 2nd isotope of hydrogen
The 2nd isotope of hydrogen is Deuterium (hydrogen-2)
The 3rd isotope of hydrogen
The 3rd isotope of hydrogen is Tritium (hydrogen-3)
The 3 isotopes of hydrogen are: Hydrogen (hydrogen-1) Deuterium (hydrogen-2) Tritium (hydrogen-3). They all have a different mass and tritium is radioactive, but what is the same about them?
The 3 isotopes of hydrogen all have a different mass and tritium is radioactive, but they all have identical chemical properties
Relative atomic mass
Relative atomic mass is an average mass taking into account the different:
1. Masses
2. Abundances (amounts)
of all the isotopes that make up the element
The formula for relative atomic mass (Ar)
The formula for relative atomic mass (Ar) is:
Relative atomic mass (Ar) = Sum of (isotope abundance x isotope mass number) ÷ Sum of abundances of all the isotopes
A very popular example of a pair of isotopes
A very popular example of a pair of isotopes are:
- Carbon-12
- Carbon-13
Number of PEN in carbon-12
The number of PEN in Carbon-12 are:
- 6 protons
- 6 electrons
- 6 neutrons
Number of PEN in carbon-13
The number of PEN in Carbon-13 are:
- 6 protons
- 6 electrons
- 7 neutrons
Why is relative atomic mass (Ar) used, instead of mass number when referring to the element as a whole?
Relative atomic mass (Ar) is used, instead of mass number when referring to the element as a whole, because many elements can exist as a number of different isotopes
If an atom gains 1 or more electrons, it gains an overall negative charge, because it has more electrons than protons.
The atom has become a what?
The atom has become a negative ion
Samples of different isotopes of an element have different physical properties.
Example
For example, they will have a different density and they: 1. May Or, 2. May not be radioactive
Samples of different isotopes of an element always have the same chemical properties, because what?
Samples of different isotopes of an element always have the same chemical properties, because their reactions depend on their electronic structures
The 3 isotopes of hydrogen all have a different mass and tritium is radioactive, but they all have identical chemical properties.
Example
For example, the 3 isotopes of hydrogen all react with oxygen to make water
