Period Table- Elements And Atoms Flashcards
(12 cards)
Why are noble gases unreactive?
Because noble gases have a complete outer shell of electrons making them stable. This stability means they don’t need to gain, share or lose electrons.
Why are noble gases unreactive?
Because noble gases have a complete outer shell of electrons making them stable. This stability means they don’t need to gain, share or lose electrons.
How does the density change as you decrease down group 0?
The density increases because as you move down the noble gases, the atomic mass increases due to the addition of more protons and neutrons in their nuclei.
What happens to the boiling/melting point as you go down group 0?
As you decrease down the group, atoms increase in size as they have more electron shells. The intermolecular forces become stronger so more energy is needed to break these forces, therefore there is a higher boiling/melting point going down.
What happens to the reactivity of metals as you go down group 1?
The reactivity increases because the outer electron is furthest from the nucleus and therefore easier to lose. This increased distance weakens the attraction between the nucleus and outer electron meaning it requires more energy to try keep it.
How does the density change going down alkali metals?
Overall, the density generally increases because the increase in atomic mass is more significant than the increase in atomic size.
What happens to the melting and boiling point of group 1?
They decrease because the size of the atomic radius (distance from the nucleus to the outer electron) increases, meaning the electrostatic attraction decreases and metallic bonds become weaker. This results in less energy being required to break these bonds.
What happens to the reactivity as you go down group 7?
The reactivity decreases because the outer electrons become further from the nucleus as the atomic size increases, making it harder for the halogens to gain an electron and become stable.
How does the density change as you go down group 7?
The density of the halogens increases due to the additional amount of protons and electrons in the nucleus which outweighs the increase in atomic volume.
What happens to the melting and boiling point going down group 7?
Melting and boiling point increases. This is because the atoms increase in size leading to stronger intermolecular forces which require more energy to break.
The timeline of the Atom and what these people discovered
1803 John Dalton- Discovered Particles remain unchanged during a chemical reaction.
1879 JJ Thomson- Discovered the plum pudding model. A ball of positive charge with negative electrons embedded.
1911Rutherford- Alpha particles mostly passed straight through so most of the atom is empty space. A few alpha particles deflected through large angles so mass is concentrated at the centre of the atom and nucleus is positively charged.
1913Bohr- Suggested eectrons move in fixed orbits, called electron shells, around the nucleus.
1932Chadwick- Discovered the neutrons within the nucleus
Isotopes
Atoms with of the same element with the same number of protons but different number of neutrons
