4.2

~Periodic Trends~

In 4.2 we learned about valence electrons. We also learned how to define atomic radius and know how the radius is largest at the bottom-left and smallest at the top-right. We learned about ionization energy and electronegativity and how protons and energy levels affect the reactivity of elements. 

Need to Know

- How to determine the number of valence electrons

- How to define the atomic radius

- What ionization energy and electronegativity is and the trends they follow

- Comparing the character and reactivity of different elements and justify these trends by using ionization energy and electronegativity

4.2 was slightly difficult when it came to first understanding electronegativity and ionization energy.

We need to know this information so we can know how many valence electrons are in an element and why they react the way they do. We can also know the atomic radius of an element based on its location on the periodic table.