When we look at the periodic table, we can see some cool patterns that help us understand how different elements act.
Energy Levels: As we go down a column in the table, each element has one more energy level than the one above it.
For example, lithium (Li), which has an atomic number of 3, has the electron arrangement of 1s² 2s¹.
But when we look at sodium (Na), it has an arrangement of 1s² 2s² 2p⁶ 3s¹.
This extra energy level means the outer electrons are farther from the nucleus, and that can change how reactive the element is.
Valence Electrons: Elements in the same column have similar outer electron arrangements. This means they have the same number of valence electrons.
For instance, alkali metals like lithium, sodium, and potassium all have one valence electron in their outer shell (s¹), which makes them very reactive.
Filling Order: Across a row in the table, electrons fill subshells in a certain order based on energy levels.
This order usually goes like this: s → p → d → f.
Understanding this order helps explain other patterns, like why electronegativity (how much an atom wants electrons) and ionization energy (how hard it is to remove an electron) increase as you move from left to right.
Stability: Subshells that are completely full or half-full are especially stable.
For example, neon (Ne) has the arrangement 1s² 2s² 2p⁶ and is very stable because its outer shell is full.
These patterns are super helpful to predict how elements will behave and react. They make learning about the periodic table a lot more interesting!
When we look at the periodic table, we can see some cool patterns that help us understand how different elements act.
Energy Levels: As we go down a column in the table, each element has one more energy level than the one above it.
For example, lithium (Li), which has an atomic number of 3, has the electron arrangement of 1s² 2s¹.
But when we look at sodium (Na), it has an arrangement of 1s² 2s² 2p⁶ 3s¹.
This extra energy level means the outer electrons are farther from the nucleus, and that can change how reactive the element is.
Valence Electrons: Elements in the same column have similar outer electron arrangements. This means they have the same number of valence electrons.
For instance, alkali metals like lithium, sodium, and potassium all have one valence electron in their outer shell (s¹), which makes them very reactive.
Filling Order: Across a row in the table, electrons fill subshells in a certain order based on energy levels.
This order usually goes like this: s → p → d → f.
Understanding this order helps explain other patterns, like why electronegativity (how much an atom wants electrons) and ionization energy (how hard it is to remove an electron) increase as you move from left to right.
Stability: Subshells that are completely full or half-full are especially stable.
For example, neon (Ne) has the arrangement 1s² 2s² 2p⁶ and is very stable because its outer shell is full.
These patterns are super helpful to predict how elements will behave and react. They make learning about the periodic table a lot more interesting!