In geology, it would be an epoch, but in other areas, it would completely depend on what periods of time you are referring to.
after Jurrasic period it is the Cretaceous period
Silicon is in period 3 on the periodic table. It is the second element in the period, following sodium.
Sulfur is in the 3rd period.
Hydrogen is located on the first period; the first row in the periodic table.
chlorine is in period 3, group 17
subcategory
is 422.0 a category, subcategory, or subclassification?
No, not yet. But when there are enough questions on the topic, a subcategory might certainly be opened.
is code 986 a category, subcategory, or subclassification
is code 986 a category, subcategory, or subclassification
No, there is no limit to the amount of questions per category or subcategory.
The subcategory called "English to Latin" can be found here:http://wiki.answers.com/Q/FAQ/4109
There is a subcategory for Super Smash Bros at this link:http://wiki.answers.com/Q/FAQ/3437
Yes, there is. Here is the link to the subcategory called Break Dancing:http://wiki.answers.com/Q/FAQ/8158
A subcategory; category
You cannot create a new subcategory yourself.(See the Related question for information about requesting a new category.)
The category called "Cleaning" is a subcategory of Home and Garden, whereas the subcategory of "Cleansing" is a subcategory of Alternative Medicine. The former category deals with questions about cleaning in your home; the latter pertains to the state of health of your body.