4 ms·
I remember having a periodic table as a kid on which helium was present twice. Seems like a good compromise.
by yoz-y 8y ago
I remember having a periodic table as a kid on which helium was present twice. Seems like a good compromise.
- Pulcinella 8y agoI’ve also seen ones with hydrogen placed twice, above lithium and above fluorine. In reactions hydrogen likes to gain an electron like the halogens rather than lose one like the alkali metals.