characteristic of a property that indicates if it can undergo a certain chemical change
What are two components of a chemical change?
alters composition
a new substance is formed
What are five evidences of a chemical change?
change in odor
change in color
gas released
light/heat released/absorbed
formation of precipitate
What are four examples of a chemical change?
rotting
rusting
burning
cooking food
What are two examples of a chemical property?
flammability
reactivity with acids
What are three examples of phyical properties?
density
color
melting point
What is a phyical property?
characteristic of a substance that can be observed without changing the substance itself
What are two components of a physical change?
doesnt change composition
original substance can be recovered
What are three examples of physical changes?
tearing
crushing
melting
How is atomic size measured?
by determining distance between nuclei of two atoms pushed together and dividing that distance by two to get the atomic radius
As atoms go down a group, do they increase or decrease? Why?
They increase becasue there are higher energy levels.
As atoms go across a period do they increase/decrease? Why?
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.
Is an atom or its cation smaller? Why?
A cation is smaller because it has more protons vs electrons so the protons pull the electrons closer to them
Is an atom or its anion smaller? Why?
An atom would be smaller because there are more electrons than protons in an anion, so the electrons would pull away from the protons.
What is ionization energy?
the energy needed to remove an electron from an atom
Does ionization energy increase or decrease going down a group? Why?
Ionization energy decreases going down a group because there is less attraction owing to the distance between protons and electrons.
Does ionization energy increase or decrease going across a period?
It increases because there is a greater attraction between protons and electrons as the space between p+ and e- decreases
What is one exception in the rule about ionization energy and periods?
Atoms closer to the noble gases are less stable, so ionization energy is less for them.
Author
alipeace11
ID
67514
Card Set
Chemistry: (b) Chemical/physical changes, atomic/ionic size and ionization energy