Question : Ex. The smallest atom in Group VI-A -oxygen atom
The most metallic element in Group VII-A - Astatine
The most stable element in period 5 - Argon
The smallest atom in period 2- Neon
Now, how do I determine the element with most compact size?
Is it related to the atomic size/radius?
Answer : Element Ar, argon, has the most compact size in Period 3 because it has the most protons in the period. That means that it has the most strength to pull in the electrons, making it the most compact.
That's why when you go from left to right across a period, atomic radius decreases.
Question : and what is an activity series?
will an alkali metal have a very high first ionization energy?
are the ionization energies of the noble gases very low?
is the electron configuration of an atom related to its reactivity?
and are s and p orbitals always empty for the noble gases?
please try to answer all my questions.
Answer : Bromine is not isoelectronic with any noble gas. BROMIDE ion (Br-) is isoelectric with Krypton
Activity series? U mean electrochemical series? It is a series listing from the most reactive elements to the least reactive elements. It is useful to deduce which element is more reactive than the other and hence, you can deduce which element can displace the other element via displacement reactions.
Alkali metal is Group I metal, the first ionisation energy is not very high. The highest first ionisation energy would be noble gases because they already have 8 valence electrons. Removing one electron from the stable octet structure requires a lot of energy.
Hence, ionisation energy of noble gas CANNOT be low.
The electron configuration of an atom RESULTS in the chemical behaviour of the atom, how it behaves when it forms bonds with other elements, whether it is reactive or not reactive etc.
s and p orbitals are always full for noble gases! they have full octet structure, meanin..
Question : Like one example is Carbon-14 dating but what other elements are used to determine the half life?
Answer : The half-life of carbon-14 is only 5730 years, so the method cannot be used for materials older than about 70,000 years. Other radiometric dating involves the use of isotope series, such as rubidium/strontium, thorium/lead, potassium/argon, argon/argon, or uranium/lead, all of which have very long half-lives, ranging from 0.7 to 48.6 billion years.