Chapter 3: Electrons in atoms Flashcards
What is the Principle quantum Shells?
they are regions at various distances from the nucleus that may contain up to a certain number of electrons. The first quantum shell contains up to 2 electrons, the second up to eight and the third up to 18.
What is the electronic configuration?
It is a way of representing the arrangement of electrons in atoms showing the principle quantum shells, the subshells and the number of electrons present. the electrons may also be shown in boxes.
What is ionization energy?
it is the energy needed to remove 1 mole of electrons from1 mole of atoms of an element in the gaseous state to form1 mole of gaseous ions.
What is successive ionization energies?
Hi1, Hi2 and so on, it is the energy required to remove the first, then the second and then the thridelectrons and so on from a gaseous atom or ion, producing an ion more positive with one more positive charge each time. it is measured in kJ per mole.
What are the two main characteristics of successive ionization energies?
- It consistently increases because the attarctive forces with the positive charges increases.
- there are occasional big jumps because the energy level becomes closer to the nucleus so the attractive force becomes stronger.
What are the three main factors that influence successive ionization energies?
- the size of the nuclear charge: Higher proton numbers increase the attractive force.
- The Distance of outer electrons from the nucleus: the force of attraction decreases as the elctrons gets further and further away.
- Shielding effect of inner electrons: it is the ability of inner shell eelctrons to reduce the effective charge on electrons in the outer shell by exerting a repulsion.
describe the successive ionization energies of sodium (11 protons).
- taking out the outer shell electron is rather easy due to high shielding and large distance.
- the 8 electrons in the second shell progressively get harder to remove due to increasing attractive forces.
- the last two are ver hard to remove due to neglible shielding, small distance and high positive charge.
What is th purpose of interpreting successive ionization energies?
- To confirm the electronic configuration
2. To confirm the umber of outer shell electrons.
What are subshells of and atom?
they are regions in the principle quantum shells thathave different energy levels depending on their distance from the nucleus.
what are the maximum numers of electrons that can be in each subshell?
s = 2 p = 6 d = 10
What are atomic orbitals?
they are regions of space outside the nucleus that’s can be occupied by one or, at most, two electrons. They have different shapes.
explain how the shells and orbitals of electrons are filled.
they are filled by the electron with the lowest energy. this is in order for the lectron to be as stable as possible.
explain how an electronic configuration is represented.
the principle quantum shell is a big number.
the subshell is represented by either an s,p,d or f. and finally, the number of electrons is represented by an uppercase number.
explain the relationship between the periodic table and orbitals.
groups 1 and 2 go into an s block alongside He and H.
Groups 3 - 8 go into a p block.
and finally, the transition elements go into a d block.
why do electrns spin in opposite directions?
to reduce the repulsion effect.