5.3 : Periodic Trends

Essential Question: What trends (patterns) in properties of the elements are shown by the periodic table?

• The periodic table shows trends in atomic size, ionization energy, electron affinity and electronegativity.

• The periodic table shows trends in color and taste of elements.

• The periodic table shows trends in the number of isotopes and ions of each element.

• The periodic table shows trends in the melting and boiling points of elements.

An ion is:

• a molecule with a neutral charge due to a full valence shell

• an atom with a + or - charge due to gaining or losing an electron

• a type of chemical bond that makes an element more stable

• neutral atom with equal protons and electrons

What is ionization energy?

• The amount of energy required to remove a valence electron from an atom

• The amount of energy released when an electron is added to an atom

• The amount of energy required to split a molecule into atoms

• The amount of energy released during a chemical reaction

The octet rule is:

• A principle that atoms are most stable with eight electrons in their valence shell.

• A rule that states atoms are most stable with six electrons in their valence shell.

• A guideline that suggests atoms are most stable with ten electrons in their valence shell.

• A theory that atoms are most stable with four electrons in their valence shell.

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Electronegativity is:

• a measure of the ability of an atom to attract electrons in a chemical bond.

• the energy required to remove an electron from an atom.

• the ability of an atom to donate electrons.

• the energy change when an electron is added to an atom.

Tags

NGSS.HS-PS1-1

a periodic trend is...

• A pattern or regular variation of properties of elements with increasing atomic number.

• A random occurrence of properties in elements.

• A trend observed in the physical state of elements only.

• A trend that is unrelated to the atomic structure of elements.

True or False: Atomic size/radius is influenced by electron configurations.

• True

• False

Get your periodic Table: Which answer lists the elements in order of decreasing radius?

• Al, Na, P, S

• Na, Al, P, S

• S, P, Al, Na

Atomic radii decrease across a period because:

• the number of electron shells increases.

• the nuclear charge increases, pulling electrons closer.

• the number of protons decreases.

• the atomic mass decreases.

As the number of protons increases, what happens to the nuclear charge (pulling power)?

• The nuclear charge increases.

• The nuclear charge decreases.

• The nuclear charge remains the same.

• The nuclear charge fluctuates.