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Chemistry A level basics need help

ionic charge ,ionic size ,atom radius ,shielding , electron density nuclear charge .I literally don't understand
Original post by helpmeplz101
ionic charge ,ionic size ,atom radius ,shielding , electron density nuclear charge .I literally don't understand

Hi, if you are confused about the basics of a level chemistry, I would recommend watching YouTube videos on the topics. I highly recommend Tyler De Witt as he teaches chemistry basics from the ground up
Original post by helpmeplz101
ionic charge ,ionic size ,atom radius ,shielding , electron density nuclear charge .I literally don't understand

Ionic charge is just the charge on the ion. For a sodium (Na+) ion, the charge is +1, whereas for the sulphate ion (SO42-), the charge is -2.

Nuclear charge is the number of protons (because each proton has a +1 charge).

Atomic radius is the distance between the centre of the nucleus and the outer electrons. Atomic radius decreases across a period because the atoms have the same number of electron shells, but more protons in their nucleus (so the nucleus has a greater positive charge and pulls the electrons inwards, towards itself).
The term 'ionic radius' is sometimes used for ions instead of 'atomic radius' - some exam questions may refer to the 'ionic radius' of group 1 and 2 metals, for instance, because metals consist of positively charged ions surrounded by a sea of delocalised electrons (in the metallic bonding topic).

Shielding describes how the electrons in the outer shell are repelled by electrons in the inner shells. So, the more shells an atom has (number of shells increases down a group), the greater the degree of shielding, because there are more inner electrons to repel the outer electrons. (This repulsion is what makes it easier for the outer electrons to be lost.)

Electron density basically refers to how electrons distribute themselves within a molecule - a more electronegative element (Cl, N, O, F) will withdraw (pull) electrons towards itself within a molecule, so the area around that atom will be more electron dense. Similarly, C = C bonds in alkenes have four electrons (a covalent bond is a shared pair of electrons, so a double bond = 2 shared pairs = 4 electrons) and so have quite a high electron density in that part of the molecule.
Hope this helps! x
Thank u so so so mucchhhh
Original post by helpmeplz101
ionic charge ,ionic size ,atom radius ,shielding , electron density nuclear charge .I literally don't understand

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