There are four pairs of electrons around the central carbon atom of methane. These pairs each consist of one electron originally from the carbon and one from the hydrogen atom bonded to it.
Though the question only considers the outer shell of electrons, as that is the only shell used for bonding, it may be useful to remember that in methane the carbon atom has a total of ten electrons around it, due to its two inner electrons.
Let us get number atoms of the constituent first.4 grams CH4 (1 mole CH4/16.042 grams)(6.022 X 1023/1 mole CH4)= 1.5 X 1023 atoms of methane========================so,Carbon is one to one in the molecular formula, so let's get the number of hydrogen atoms in this mass methane.1.5 X 1023 atoms CH4 (4 mole H/1 mole CH4)= 6 X 1023 atoms hydrogen======================now, we proceed to find electrons1.5 X 1023 atoms carbon * 6 electrons= 9 X 1023 electrons carbon--------------------------------------6 X 1023 atoms hydrogen * 1 electron= 6 X 1023 electrons hydrogen--------------------------------------------added together= 1.5 X 1024 electrons in 4 grams methane-------------------------------------------------------------( call it 2 X 1024 electrons methane to be in line with significant figures )
For groups 1-2 the number of valence electrons is equal to the number of the group.For groups 13-18 the number of valence electrons is equal to the number of the group, but with numbering starting up from 3 (13), 4 (14) , etc. (transition metals excluded).
To find the number of valence electrons for an element in the representative groups (Group 1, 2, 13-18), you can look at the group number. Elements in Group 1 have 1 valence electron, Group 2 have 2 valence electrons, Group 13 have 3 valence electrons, and so on up to Group 18 which have 8 valence electrons. The group number gives you the number of valence electrons for elements in the representative groups.
The atomic number from a periodic table is the number of electrons each known element has in its orbit. The atomic number of Xe is 54, therefore Xenon (Xe) has 54 electrons in its orbit.
The group number of an element on the periodic table corresponds to the number of valence electrons it has. For main group elements (groups 1, 2, 13-18), the ones digit of the group number gives the number of valence electrons. For transition metals and inner transition metals, the number of valence electrons can vary.
Let us get number atoms of the constituent first.4 grams CH4 (1 mole CH4/16.042 grams)(6.022 X 1023/1 mole CH4)= 1.5 X 1023 atoms of methane========================so,Carbon is one to one in the molecular formula, so let's get the number of hydrogen atoms in this mass methane.1.5 X 1023 atoms CH4 (4 mole H/1 mole CH4)= 6 X 1023 atoms hydrogen======================now, we proceed to find electrons1.5 X 1023 atoms carbon * 6 electrons= 9 X 1023 electrons carbon--------------------------------------6 X 1023 atoms hydrogen * 1 electron= 6 X 1023 electrons hydrogen--------------------------------------------added together= 1.5 X 1024 electrons in 4 grams methane-------------------------------------------------------------( call it 2 X 1024 electrons methane to be in line with significant figures )
For groups 1-2 the number of valence electrons is equal to the number of the group.For groups 13-18 the number of valence electrons is equal to the number of the group, but with numbering starting up from 3 (13), 4 (14) , etc. (transition metals excluded).
The total number of electrons in any atom is the same as the atomic number. The number of valence electrons in an atom in columns 13 - 18 is the second digit of the column number.
In methane, the combined protons from the carbon and hydrogen, are equal in number to the combined amount of electrons. This gives a total net charge of 0, it is neutral.
The groups have equal number of valence electrons. The elements in same groups have same chemical properties.
Group 8
Groups on the periodic table are numbered from 1 to 18, with the group number corresponding to the number of valence electrons in the elements of that group. Group 1 elements have 1 valence electron, group 2 elements have 2 valence electrons, and so on. Groups 1, 2, and 13-18 are known as the main group elements.
To find the number of valence electrons for an element in the representative groups (Group 1, 2, 13-18), you can look at the group number. Elements in Group 1 have 1 valence electron, Group 2 have 2 valence electrons, Group 13 have 3 valence electrons, and so on up to Group 18 which have 8 valence electrons. The group number gives you the number of valence electrons for elements in the representative groups.
For Groups 1 and 2 the valence number is the group number, for groups 13-18 it is the last digit of the group number so oxygen (group 16) would have 6 valence electrons. For all the other groups ( group 3-12, the transition metals ) they are variable.
atoms in a group have the same number of valence electrons
1,2 and 13-18 the number is how many valence electrons it has.
For the group 1 and 2 elements, the group number is the number of valence electrons. For groups 13 - 18, subtract 10 from the group number to get the number of valence electrons.