C1 - Atomic Structure and the Periodic Table Flashcards
You should know this Tinh, you idiot, it's easy!
Element
A substance made of only one kind of atom.
Compound
A substance made of more than one kind of atom, chemically bonded.
Mixture
A mixture of substances, not joined together.
Empirical Formula
The simplest ratio of atoms in each element or compound.
What particles are contained in the nucleus of an atom?
Protons and Neutrons
What charge do electrons have?
Negative Charge
Isotope
Different forms of an element, with different numbers of neutrons.
Are the reactivities of isotopes different?
No, as the electron structure remains the same.
What is atomic number?
The number of protons that an atom has. This is what defines the element of the atom.
What particle in an atom defines its reactivity?
Electrons
What is Atomic Mass?
The total mass of an atom. Each proton and neutron has a mass of 1, while an electron has a mass of 1/1836, but is usually ignored, as the value is very small.
Different isotopes of an element will have different…
Atomic mass
What is Relative Atomic Mass?
The average mass of atoms takes account of the abundances of the isotopes of the element. The mass is compared to 1/12th of the mass of a Carbon-12 atom.
How is relative atomic mass calculated?
By multiplying the mass of every isotope by its percentage abundancy, adding them all together, and dividing by 100.
What is electron configuration?
The way the electrons are placed throughout an atom.
Where are electrons on an atom?
They are based in energy levels, or “shells” which orbit the nucleus.
Which shell is filled first by electrons in an atom?
The innermost shell.
What is the electron structure of magnesium?
2,8,2
The ….. electrons an atom has in its outer shell, the more reactive it is.
Less
Why do atoms in the same group have similar reactivities?
Because the number of electrons in their outer shell is the same.
Why is caesium more reactive that lithium?
Because the more shells there are, the harder it is for the electrostatic forces of the nucleus to attract the electrons, so the easier it is for the electrons to be lost.
The group number of an element is the number of ……………….
Electrons that it has in its outer shell.
The period number of an element is the number of ………….. it has.
Electron shells
What are ions?
Ions are atoms with a charge.
What are positive ions called?
Cations.
What are negative ions called?
Anions.
What types of elements form cations?
Metals and hydrogen form cations by losing the electrons in their outermost shell.
What types of elements form anions?
Non-metals and hydrogen form anions by gaining electrons to fill their outermost shell.
Why do atoms form ions?
To fill their outer shell and become stable like the Noble gases.
What happens when metals and non-metals react?
The metals lose the electrons in their outer shell, which are gained by the non-metals, filling their outer shell, making metal cations and non-metal anions. Because of their opposite charge, they are attracted together and form a large lattice.
