Y9 - Atom structure Flashcards
What are the structures in an atom?
the nucleus which contains protons and neutrons, electrons and electron shells
How many electrons can the first 3 electron shells hold?
2,8,8
What is the relative mass of a proton or a neutron
1
What is the relative mass of an electron
1/1836
What is the charge of the different sub-particles?
1 - proton, 0 - neutron and -1 - electron
What is synonym for electron shells?
Energy levels
How are elements on the chemical table of elements represented?
With the symbol of the element, the mass number at the top left of the symbol in small letters and the atomic number at the bottom left of the symbol
What is the atomic number?
The number of protons in the atom, which is also equal to the number of electrons in an atom.
Is an atom positively or negatively charged?
An atom is not charged at all as the negative charge of the electrons cancel out the positive charge of the protons.
How are the number of neutrons in an atom of a specific element calculated?
The mass number - the atomic number.
Where are electrons in the atom?
Electrons move around energy levels/ electron shells that are in circular orbits around the nucleus of the atom.
What are Isotopes?
Isotopes are elements that always have the same number of protons, but the number of neutrons they have varies.
What is the identity of an element?
Number of protons
What is the table that contains all the elements called?
Periodic table of elements
What is the definition of an ionic compound?
A chemical compound formed by oppositely charged ions, held together by strong electrostatic forces
What is a lattice?
A repeating regular arrangement in atoms or ions.
Why do ionic compounds have high melting point?
Ionic compounds have high melting points because of the strong forces of electrostatic attraction between positive and negative ions which requires lots of energy to overcome and therefore a high temperature.
When do ionic compounds conduct electricity?
When molten or aqueous because the charged ions are free to move. However, when solid the charged ions are not free to move as they are fixed in an ionic lattice
