UNIT 2 - How Atoms Become Ions Flashcards
Lesson (02/03/2025)
What is an ion?
Atoms that gained or lost electrons, resulting in a charge.
What is a positive ion?
An atom that loses electrons and becomes positively charged.
Why do metals become positive ions?
Metals have 1, 2, or 3 valence electrons and want to lose them.
What is a negative ion?
An atom that gains electrons and becomes negatively charged.
Why do nonmetals become negative ions?
Nonmetals have more than 3 valence electrons and want to gain them.
What is reactivity in elements?
Reactivity is linked to how close an element is to having a full valence shell.
Which groups contain the most reactive elements?
Group 1 and 17, as they are only one electron away from a full valence shell.
Example of a reactive element from Group 1?
Sodium easily gives up an electron to expose the full valence shell underneath.
Sodium is in Group 1.
How does reactivity change down a group?
Reactivity increases as you move down the family.
Example of reactivity in Group 1 metals?
Potassium is more reactive than sodium.
This illustrates the trend in reactivity.
How does atomic size change moving down a group?
Atomic size increases as you move down a group.
Why does atomic size increase down a group?
Elements have more energy shells, making the atoms larger.
How does atomic size change moving left to right across a period?
Atomic size decreases moving left to right across a period.
Why does atomic size decrease across a period?
The number of protons increases, pulling valence electrons closer to the nucleus.
