Periodic Trends Flashcards
What is atomic radii
Size of the atom, from the center of the nucleus to the valence electrons
What is ionization energy
The energy requires to remove an electron from an atom
What is electronegativity
How much an atom attracts other atoms
What is electron affinity
The amount of energy released when the atom gains an electron
Atomic radii-period trend, why
Decreases, the protons are attracted to the electrons so the more protons the higher the attractive energies and the valence level is pulled closer to the nucleus
Atomic radii-group trend, why
Increases, an energy level is added for each period, increasing size
Ionization energy-period trend, why
Increases, when the electrons are closer to the nucleus the attractive energies are higher making it more difficult to remove the electron from the atom
Ionization energy-group trend, why
Decreases, in larger atoms the electrons are further from the nucleus, decreasing attractive forces making it easier to remove them from the atom
What happens to ionization energy when an electron is removed
Increases
More than one - electrons repel each other so when one is removed they sink closer in toward the nucleus
One - there is one less energy level
With electrons closer to the nucleus it’s harder to remove them
Electronegativity-period trend, why
Increases (with exceptions), with a smaller size the nucleus is closer to the outside of the atom
Electronegativity-group trend, why
Decreases or stays the same (with exceptions), with a larger size the nucleus is further from the outside of the atom
Metal reactivity-period trend, why
Decreases, across periods size decreases which means more energy is needed to remove an atom/react so there is a smaller reaction
Metal reactivity-group trend, why
Increases, down groups size increases which means less energy is needed to remove an atom/react so there is a bigger reaction
Nonmetal reactivity-period trend, why
Increases, the size of the atom is smaller so it has a higher ability to attract electrons making it more reactive
Nonmetal reactivity-group trend, why
Decreases, the size of the atom is larger so it has a decreased ability to attract electrons making it less reactive
Electron affinity-period trend, why
Increases, the atoms are smaller with a higher ability to attract electrons so there is more energy released when one is gained
Electron affinity-group, why
Decreases, the atoms are larger with a decreased ability to attract electrons so there is less energy released when one is gained
How do you determine the number of protons
The atomic number
How do you determine the number of electrons
Atomic number
How do you determine the number of neutrons
Subtract the number of protons from the weight (number next to element name)
How do you determine the number of valence electrons
One’s digit of the group number, unless they are in groups 3-12, then it is unknown
How do you determine energy levels
The period number
