Group 3

Group 3 elements, otherwise known as rare-earth elements are a group of metals that contain a variety of uses from making electronics to fertilization of crops to being a power source or making extremely powerful magnets. They include the elements scandium, yttrium, and all lanthanides

Actinides are NOT considered rare-earth elements, but are still considered group 3 elements and the elements in the actinides are heavy homologues of their lighter correspondence in the lanthanides. Actinides, like lanthanides are f-block elements , soft, and they are chemically similar however, the major difference between actinides and lanthanides is that actinides are radioactive and can be very deadly whereas lanthanides do not have an effect on the body and are generally safe.

All rare-earth elements in the Seasonal-Space modpack can be obtained via monazite ore, along with the actinide, thorium. Many of the lighter lanthanides along with yttrium can be obtained via bastnäsite.

### Rare-Earth elements

Rare-Earth elements are the non-radioactive group 3 elements like scandium, yttrium, and every lanthanide except promethium with a variety of uses such as catalysts, electronics, space and many more. Although they're referred to as "rare-earth elements" they aren't that rare given how easy it is to obtain the principal ores of those elements, bastnäsite and monazite. However the method to extract these elements(see monazite and bastnäsite) from the aforementioned ores is hard which is partially where the name "rare-earth" came from.

#### Lanthanide

Lanthanides are a group of rare-earth from lanthanum to lutetium that has a variety of uses from phosphor making, communications, and a whole host of things.

The thing that separates lanthanides and the lighter group 3 elements are the fact that it is the first row within the f-block series of elements.

All the lanthanides currently within the SeasonalSpace modpack at the moments are, from lowest atomic number to highest, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, and lutetium.

### Actinide

Actinides are the second row of f-block elements with a majority of them having little to no natural occurrence due to having half lives ranging from minutes to a few hundred thousand years. The two actinides that can occur in nature in bulk are thorium and uranium with a half life of 10 billion and 100 million to 1 billion years respectively.

The principal ore for all naturally occurring actinides is pitchblende, which generally has high concentrations of both uranium and thorium along with trace amounts of protactinium, radium, and polonium(though the latter 2 are not actinides) from nuclear decay. Transuranic elements are generally obtained via the solar neutron activator(added by mekanism) that converts U-238 into heavier and heavier elements albeit, neptunium, plutonium, and americium can appear in small quantities in ores and in nature. Anything beyond americium are completely absent in nature and MUST be synthesized through the aforementioned method.

Actinides generally only have two uses depending on their atomic properties, either as an energy source, or for the synthesis of elements that can be used as energy.