C2a Topic 1 - Atomic Structure and the Periodic Table Flashcards
What does the nucleus contain
Protons and neutrons
What overall charge does the nucleus have
The nucleus has an overall positive charge because protons are positively charged and neutrons have no charge.
Almost the whole mass of the atom is concentrated in the ___________
Nucleus!
The nucleus is tiny compared to the …
Atom as a whole
Electrons move around the
Nucleus
Electrons have a
Negative charge (electrons and protons have equal but opposite charges)
Electrons are tiny compared to the …
Nucleus, but as they move around they cover a lot of space
Electrons occupy
Shells
The number of protons =
The number of electrons
What is the relative mass and relative charge of the atomic particles
1) Protons have a mass of 1 and a charge of +1
2) Neutrons have a mass of 1 and a charge of 0
3) Electrons have a mass of 1/2000 and a charge of -1
What is the Octet rule
The first shell can only take 2 electrons. The second shell can take a maximum of 8 electrons. The third shell can also only have a max of 8 electrons. The fourth shell can only hold 2 electrons.
Elements consist of only one type of
Atom!
Each element has a different …
Proton number!
The mass number tells us…
The total number of protons and neutrons in the atom
The atomic number tells us…
The number of protons in the atom (and so the number of electrons too)
Isotopes are…
Different atomic forms of the same element, which have the SAME number of PROTONS but DIFFERENT numbers of NEUTRONS
How do you calculate Relative Atomic Mass
1) First, multiply the mass of each isotope by its relative abundance.
2) Add those together.
3) Divide by the sum of the relative abundances.
What did Mendeleev do
1) He arranged the elements in groups.
2) He arranged the 50 or so known elements according to their properties and the properties of their compounds to make a Table of Elements.
3) He placed elements with similar chemical properties in the same vertical groups - but he found he had to leave gaps in his table to make this work.
What did Mendeleev’s table do
The gaps in Mendeleev’s table of elements predicted the properties of undiscovered elements.
What are periods
1) The rows on the periodic table.
2) The elements are arranged in order of increasing atomic number along each row.
3) The period number is the same as the number of electron shells e.g. The period 3 elements have 3 electron shells.
4) The properties of elements change as you go along a period.
What are groups
1) The columns on the periodic table.
2) Elements in the same group have similar properties.
3) Elements in the same group have the same number of electrons in their outer shell.
4) The properties of elements often gradually change as you go down a group (as the atomic number increases).
Where is the nucleus
Middle of the atom
