The first period in which you'll find 18 elementSis the fourth (4th) period: going from 19-K (potassium) to 36-Kr (Krypton).
Maybe this is the answer to the question you didn't ask but probably meant to ask.
(It is impossible for one element to contain 18 elements, you see!)
The element with 18 electrons in the 3rd period (= row) of the Periodic Table is Argon
In the first period of the periodic table there are only two elements: H (1 eln.) and He (2 eln's) and have nothing to do with the number 18.
The first period in the periodic table contains two elements: hydrogen and helium. Hydrogen has one electron in its 1s orbital, while helium has two electrons in its 1s orbital.
That is not true. The first element in a period may be active or inactive, depending on the specific electron configuration of the element. For example, the first element in period 1, hydrogen, is not considered an active element.
Period 1 refers to the top row of the periodic table. These elements are Hydrogen and Helium.
litium, and elements in the 2nd period (row) are pretty common
There are 2 elements in the first period, 8, 8 elements in 2nd and 3rd periods respectively,
The first element in period three of the periodic table of chemical elements is sodium (Na).
Two elements
The fourth period contains 18 elements beginning with potassium and ending with krypton – one element for each of the eighteen groups. It sees the first appearance of d-block (which includes transition metals) in the table. Do You Agree? Sincerely, Jocelyn E.Flowers
Potassium is the element that used to be first to make fertilizer.
Each row in the table contains elements that have the same number of electron orbit shells. The first orbit, which is closest to the nucleus only has space for 2 electrons (no idea why, sorry). This is why only hydrogen (1 electron) and helium (2 electrons) are in the first row. The second row has the same inner shell, with 2 electrons and an outer shell with room for 8...and so on.
two elements, hydrogen and helium.
two
Period 1: 2 elements Period 2: 8 elements Period 3: 8 elements Period 4: 18 elements Period 5: 18 elements Period 6: 32 elements Period 7: 25 elements
The first period or row contains only elements that are gases at standard temperature and pressure.
The first period in the periodic table contains two elements: hydrogen and helium. Hydrogen has one electron in its 1s orbital, while helium has two electrons in its 1s orbital.
No, carbon is not the first element on the periodic table of elements. Hydrogen is the first element on the periodic table.
A period is a horizontal row on the periodic table of the elements. There are seven periods on the periodic table. Each period corresponds to the highest energy level that contains electrons. For example, the elements in the first period have electrons in the first energy level, which is the only energy level available; the elements in the second period have their highest energy electrons in the second energy level; the elements in the third period have their highest energy electrons in the third energy level, and so on.