No until now no one has been able to divide electrons any further but who knows in the future
Yes, electrons have been split into two smaller particles - holons and spinons. I refer you to : http://www.bbc.co.uk/blogs/davidgregory/2009/09/splitting_the_electron.html.
No. Electrons are fundamental particles.
No. Atoms are divided into groups according to their proprieties and electron configurations.
No. The greater distance from the nucleus the more energy an electron has.
The name atom comes from the Greek ἄτομος/átomos, α-τεμνω, which means uncuttable, something that cannot be divided further. Therefore, it cannot be divided.
Leptons are divided into three families with 4 particles (2 particles, plus their two anti-particles) in each family. In the electron family we have the electron, positron, electron neutrino and electron anti-neutrino. Each family has a higher mass than the one before it so the tauon is heavier than the muon which is heavier than the electron. The physical reason for there being three families is completely unknown and will probably win you a Nobel prize if you can figure it out!
The single outer electron is further away from the nucleus and thus is less tightly bound and thus it is energetically easier to remove that electron
S block elements are elements that contain their outermost electron in the s shell. S block elements are further divided into 2 groups.
The electron is an elementary particle. This means that it cannot be broken down further. Therefore, an electron does not have a "core".
further away :)
The vertebrates are further divided into five groups or classes.
An electron in a 2s orbital is on average closer to the nucleus.
The electron cloud is divided into s, p, d, and f orbitals. These orbitals also occur at different principle energy levels.
No. Atoms are divided into groups according to their proprieties and electron configurations.
The constituent time segments are epochs and periods, which are further divided into ages.
No. The greater distance from the nucleus the more energy an electron has.
The further you are down the halogen group (group 7) the lower the 1st ionisation energy (amount of energy required to remove 1 electron from the atom) is. This is because the electron in question becomes further from the positive charge of the nucleus the more electron shells there are, and electron shielding (the blocking of the effect of the positive charge's attraction) is increased.
Japan is divided into regions and further subdivided into prefectures.
Electron shielding is not a factor across a period because they all have the same number of electron shells! No further (extra) shells means that they are all affected by electron shielding equally.