Chapter 10 (periodic Trends) Flashcards
Atoms get smaller as you move across (—->) a period (row) becuase
Protons are being added
Ionization energy
The minimum amount of energy required in order to remove an electron from the atom
Larger atoms are easier to remove an electron because
It is further alway from the nucleus and isn’t held as tightly together
Atoms get larger as you move down the group, why?
As you add energy levels, you are adding e’ at a quarter distance from the nucleus.
Smaller atoms _______ to the nucleus better.
Attract,
Big ones can get through cloud
(Noble gases not included in trend)
When a neutral atom loses an electron it’s called
A cation
What types of atoms tend tot lose electrons
Metals
When a neutral atom gains an electron it’s called
Anion
What types of atoms tend to gain electrons
Nonmetals
Periodic law
If elements arranged in order of increasing atomic mass, a pattern can be seen in which similar properties recur on a regular or periodic basis
Metals
Solid at room temp Shiny, lustrous Good conductors of heat and electricity Malleable Flexible Gives up electrons easily to form cations
Non metals
Gases or brittle solids at room temp
Dull to translucent opaque
Poor conductors of heat and electricity
Alkali metals
- located far left of periodic table (lithium, sodium, potassium..)
- soft, silvery, solids
- most reactive of all metals
- react vigorously with water to produce hydrogen gas
- one valence electrons
Group 1
Alkaline earth metals
- silver colored reactive metals
- readily form compounds with non metals
- low solubility in water
- two valence electrons
- group 2
Periodic trends
Consistent and predictable changes in elemental properties
Atomic radius
Distance from the nucleus to the boundary of the surrounding cloud of electrons
Two periodic trends
- As we move down a family, the sizes of atoms increase
- Across a period sizes decrease
Ionization energy
Minimum energy required to remove an electron from a gaseous atom or ion.
- tells us how strongly an atom holds on to its outermost electrons
- ion with low IE is more likely to lose electrons and form cations during chemical changes
- a high IE ion tendency to gain electrons and from anions or no ions
Size of atoms and IE
Larger atoms (outer electrons are held less tightly together) = lower IE
The smaller the atom (held tightly together) = higher IE
**as atomic size increases, IE decreases
Alkali metals and IE
Alkalis have the lowest IE
Electronegativity
Relative ability of a bonded atom to attract shared electrons to itself.
- atoms with higher EN tend to pull bonded electrons closer to nucleus
EN and atomic size
Smaller atoms have higher EN
Larger atoms, lower EN
PES
-energy measurement of electrons emitted from solids, gases or liquids by the photoelectric effect
Ionic bonding
Electrostatic attractive force bw oppositely charged ions produced when a metal atom transfers one or more electrons to a non-metal atom.
