+1 only for all elements (except for hydrogen)
hydrogen can have +1 and -1 as their oxidation numbers.
Group 1 elements have an oxidation number of +1.
Group 1 elements have an oxidation number of +1, group 2 elements have an oxidation number of +2, group 17 elements have an oxidation number of -1, and group 18 elements (noble gases) have zero oxidation number since they are chemically unreactive.
Elements that have a single oxidation number include group 1 elements (e.g. sodium, potassium) which have an oxidation number of +1, and group 2 elements (e.g. magnesium, calcium) which have an oxidation number of +2.
Hydrogen has -1 and +1 oxidation numbers. Other elements have +1 only
Elements with fixed oxidation numbers include alkali metals (group 1 elements) which have a +1 oxidation state, alkaline earth metals (group 2 elements) which have a +2 oxidation state, and nonmetals in group 17 (halogens) which have a -1 oxidation state in compounds.
Group 1 elements have an oxidation number of +1.
Group 1 elements have an oxidation number of +1, group 2 elements have an oxidation number of +2, group 17 elements have an oxidation number of -1, and group 18 elements (noble gases) have zero oxidation number since they are chemically unreactive.
Elements that have a single oxidation number include group 1 elements (e.g. sodium, potassium) which have an oxidation number of +1, and group 2 elements (e.g. magnesium, calcium) which have an oxidation number of +2.
Hydrogen has -1 and +1 oxidation numbers. Other elements have +1 only
Elements with fixed oxidation numbers include alkali metals (group 1 elements) which have a +1 oxidation state, alkaline earth metals (group 2 elements) which have a +2 oxidation state, and nonmetals in group 17 (halogens) which have a -1 oxidation state in compounds.
The oxidation number for K in KCl is +1, as alkali metals (Group 1 elements) typically have a +1 oxidation state. For Cl in KCl, the oxidation number is -1, as halogens (Group 17 elements) typically have a -1 oxidation state when they form ionic compounds.
The oxidation numbers for elements in Group 1A (alkali metals) are typically +1. For elements in Group 2A (alkaline earth metals), the oxidation number is typically +2.
The maximum oxidation number is theoretically equal to the number of valence electrons. For example the oxidation number of chlorine among different compounds can vary from -1 to +7. An exception for this is fluorine, which only have -1 and 0 as its oxidation numbers.
The oxidation number of Na in NaH is +1. In general, group 1 elements like sodium (Na) have an oxidation number of +1 in most compounds.
The oxidation numbers for the first 20 elements in the periodic table are typically as follows: Group 1 elements: +1; Group 2 elements: +2; Group 13 elements: +3; Group 14 elements: +4 or -4; Group 15 elements: -3; Group 16 elements: -2; Group 17 elements: -1; Group 18 elements: 0. Keep in mind that oxidation numbers can vary in different compounds and contexts.
Group 1 elements are the most electropositive in nature and have only 1 valence electron. So, they always show the oxidation state of +1.
Because they have one valence electrons, and if they lose this electron they attain an oxidation number of +1