Periodic Trends Flashcards
What do elements have in common when they are in the same group?
Similar physical and chemical properties and the same amount of valent electrons
What is Atomic Radius? What controls it?
- Atomic radius is the distance from the nucleus to the outer most orbital ring of an element
- The 3 factors that control atomic radius are the number of shells, the nuclear charge, and the amount of shielding effect
What is the shielding effect?
The shielding effect is when the electrons in the innermost shells shield the outermost electrons from the nucleus attractive force
What is nuclear charge?
The measure of the strength of the nucleus pull
What is ionic radius?
Ionic radius is the distance between the nucleus and the outermost shell of an ion. Negative ions have a higher ionic radius and positive ions have a lower ionic radius due to the difference in nuclear charge.
Define isoelectronic species
All elements that have the same number of electrons but different nuclear charges
What is ionization energy?
The amount of energy required to remove an electron from an atom or ion.
Much more energy is required to remove an electron from the 2nd most outer shell rather than the most outer shell.
What is electron affinity?
A measure of the energy lost or gained when an electron is added to an uncharged atom. The more negative the electron affinity, the stronger the atom is holding that electron in.
What is electronegativity?
Electronegativity is a measure of an atoms ability to attract shared electrons to itself.
What are the 2 laws related to mass?
Law of conservation of mass and the law of constant composition
Law of conservation of mass states that matter cannot be destroyed, or created.
Law of constant composition states that compounds always have the same percentage composition by mass.
