Chemistry: (b) Chemical/physical changes, atomic/ionic size and ionization energy

characteristic of a property that indicates if it can undergo a certain chemical change

• alters composition
• a new substance is formed

• change in odor
• change in color
• gas released
• light/heat released/absorbed
• formation of precipitate

• rotting
• rusting
• burning
• cooking food

• flammability
• reactivity with acids

• density
• color
• melting point

characteristic of a substance that can be observed without changing the substance itself

• doesnt change composition
• original substance can be recovered

• tearing
• crushing
• melting

by determining distance between nuclei of two atoms pushed together and dividing that distance by two to get the atomic radius

They increase becasue there are higher energy levels.

They decrease because as the number of electrons and protons increase, the attraction between the two increases and teh electrons are pulled in towards the nucleus.

A cation is smaller because it has more protons vs electrons so the protons pull the electrons closer to them

An atom would be smaller because there are more electrons than protons in an anion, so the electrons would pull away from the protons.

the energy needed to remove an electron from an atom

Ionization energy decreases going down a group because there is less attraction owing to the distance between protons and electrons.

It increases because there is a greater attraction between protons and electrons as the space between p+ and e- decreases

Atoms closer to the noble gases are less stable, so ionization energy is less for them.