Unit 4 periodic trends

ionic radii period trend

decreases from left to right

Anions

negatively charged ions (gain electrons). larger than their atoms.

ionic radius increases from groups ___ to ___ because of the transition from__________ to __________ then the decreasing trend resumes.

14 to 15; cations to anions.

polyatiomic ion

An ion that is made of more than one atom. group of bonded atoms with an overall charge.

notes on atomic radius

Electrons that are added to an atom have the same principal energy level. The valence electrons - those located in the outermost shell (orbit) of an atom. These are more tightly bound thus causing the atom to be smaller.

third ionization energy

Energy required to remove the third electron from an Atom.

Which nonmetal is highly reactive?

Fluorine

What is the most reactive metal?

Francium

Cations

Ions with a positive charge. smaller than the atom it came from.

Formation of Anions

always leads to an increase in atomic radius so anions are always larger than their parent atom.

monatomic ion

an ion consisting of exactly one atom. charged atom resulting from the loss or gain of electrons.

notes on atomic radius:

as the number if protons (Atomic number the same number from the periodic table like Carbon is 6) in the nucleus of an atom increases so does the atomic radius.

notes on atomic radius

as the number of protons increases so does the coulombic attraction because the positive charge is increasing. The opposite is that the more loosely held the electrons are, then the less valence or coulombic attraction. That is; it decreases as the electrons are placed further and further from the nucleus. Thus, the atom gets bigger.

When moving top to bottom in a group, ionization energy____________, meaning_____________________________________________ is required to lose electrons. Thus,_______________________________ down a group. Francium is the most reactive metal.

decreases; it becomes easier to lose electrons because less energy; metals become more reactive

When moving top to bottom in a group, electronegativity _____________, meaning____________________________________________. thus,________________________________________ down a group.

decreasing; weaker attraction for electrons; nonmetals become less reactive

Ionic Radii Definition and Trend

definition: the radius of a monatomic ion in an ionic crystal structure. trend: increased nuclear charge leads to increased coulombic attraction and nucleus pull valence electrons closer and the size decreases.

electrons occupy a relatively large region, referred to as the__________ also the________.

electron cloud; orbits.

second ionization energy

energy required to remove the second electron

Atomic Radii

gets larger from top to bottom.

Atomic Radii

gets smaller from left to right.

if moving from left to right, electronegativity tends to__________, meaning______________.

increase; greater attraction for electrons.

Ionic Radius Trend

increases down a group, decreases across a period

When moving top to bottom in a group, ionization energy__________, meaning _____________, attraction is exerted on electrons. thus, ________________________ across the period.

increasing; greater; nonmetals become less reactive.

When moving left to right across a period, ionization energy_________, meaning____________________________________. Thus,_______________________________ across a period.

increasing; it becomes harder to lose electrons; metals become more reactive.

The metals are located where on the periodic table?

left

characteristics of anions

number of electrons added to the outermost energy level must result in a valence of 8 electrons, but the nuclear charge (number of protons) remain unchanged. the electron cloud expands due to a decrease in attractive force from the nucleus and great repulsion among the electrons.

which group is larger? period 4, group 18 OR period 2, group 16

period 4, group 18

Nonmetals are located where on the periodic table?

right side

Electronegativity

the ability of an atom to attract electrons when the atom is in a compound

electron configuration

the arrangement of electrons in an atom

periodic trends

the distance between the nucleus and the outermost electron. (decreases from left to right).

first ionization energy

the energy required to remove the first electron from a neutral atom.

quick note for electronegativity

the higher the electronegativity value, the greater an atom's ability to attract electrons. knowing electronegativity values of the element helps predict the type of bond that would form between elements.

characteristics of ions

the number of electrons decreases but the number of protons remains the same. the highest energy level is the one removed. remaining electrons are pulled closer to the nucleus..

group trends

the number of protons in the nucleus- increases from top to bottom in a group.