Because it is a noble gas, it has completely filled orbitals (as to all the elements in group 18) and is chemically inert.
Main group elements have elements from groups 1 and 2, except hydrogen and groups 13 to 18. Main group elements are elements in groups who's lightest elements are shown by helium, lithium, boron, beryllium, carbon, nitrogen, oxygen, and fluorine.
"He" stands for helium in the periodic table of elements. It is a colorless, odorless, and tasteless gas that is the second lightest and second most abundant element in the observable universe. Helium is commonly used in balloons, airships, and cryogenic applications.
We all know that helium is a noble gas. It has atomic number 2 but it is placed in 18 group be because in 1st group the elements have only one electron in thier s orbital e.g. Hydrogen, lithium, sodium, potassium etc. But helium has two electron so it cannot exist in 1 group. In second group the s orbital are same but the physical and properties of helium is different from the elements present in second group. According to modern periodic table elements which have same physical properties are placed in same group. Since helium is an inert gas and its physical properties are similar to the other elements of the 18 group and also helium discoverd late so that hilium can be put in the 18 group
Group 1 Metals
Helium is located in period 1 on the periodic table.
Same number of valence electrons cause same properties. The elements with same properties are grouped together. For example- the alkali metals are placed in group-1
the elements belonging to group 1 and 2 of the periodic table are s-block elements. it includes elements in which the outermost subshell is s and that have 1 or 2 electrons in their outermost shell.
We all know that helium is a noble gas. It has atomic number 2 but it is placed in 18 group be because in 1st group the elements have only one electron in thier s orbital e.g. Hydrogen, lithium, sodium, potassium etc. But helium has two electron so it cannot exist in 1 group. In second group the s orbital are same but the physical and properties of helium is different from the elements present in second group. According to modern Periodic Table elements which have same physical properties are placed in same group. Since helium is an inert gas and its physical properties are similar to the other elements of the 18 group and also helium discoverd late so that hilium can be put in the 18 group
Main group elements have elements from groups 1 and 2, except hydrogen and groups 13 to 18. Main group elements are elements in groups who's lightest elements are shown by helium, lithium, boron, beryllium, carbon, nitrogen, oxygen, and fluorine.
Elements in the same group or column of the periodic table tend to possess the same number of valence electrons. For example, all elements in Group 1 (such as lithium, sodium, potassium) have 1 valence electron, while elements in Group 18 (like helium, neon, argon) have 8 valence electrons except for helium, which has 2.
"He" stands for helium in the periodic table of elements. It is a colorless, odorless, and tasteless gas that is the second lightest and second most abundant element in the observable universe. Helium is commonly used in balloons, airships, and cryogenic applications.
Only two: hydrogen and helium. This corresponds to the fact that there can be only two s orbital electrons in any electron shell, and the first shell has only s orbital electrons.
the elements on the far far right are called alkali metals (Group 1) and alkali earth metals (group 2)
We all know that helium is a noble gas. It has atomic number 2 but it is placed in 18 group be because in 1st group the elements have only one electron in thier s orbital e.g. Hydrogen, lithium, sodium, potassium etc. But helium has two electron so it cannot exist in 1 group. In second group the s orbital are same but the physical and properties of helium is different from the elements present in second group. According to modern periodic table elements which have same physical properties are placed in same group. Since helium is an inert gas and its physical properties are similar to the other elements of the 18 group and also helium discoverd late so that hilium can be put in the 18 group
Hydrogen is not in a group with other families. It actually is in group 1 of the Periodic Table. It is a diatomic atom when it combines with other elements.
To determine the number of valence electrons in an atom, look at the group number on the periodic table. The group number indicates the number of valence electrons. For example, elements in group 1 have 1 valence electron, while elements in group 18 have 8 valence electrons (except for helium, which has 2).
To determine the number of valence electrons in an element, look at its group number on the periodic table (group 1-18). The group number represents the number of valence electrons the element has. For example, elements in group 1 have 1 valence electron, while elements in group 18 have 8 valence electrons (except for helium, which has 2).