Particles owsam and Physical and Chemical change. Representing cc Flashcards
… are the only substances that exist as single, separate atoms in nature.
All other atoms are joined to other atoms, the same or different.
Noble gasses
The definition of a compound?
When atoms of different elements combine in a chemical reaction, in fixed ratios because of strong forces/bonds.
What are the two types of compounds that can form?
Molecular compounds: (Covalent) 2 non-metals.
Ionic compounds: (Ionic) Metal + Non-metal, positive and negative ion. Held together in a crystal lattice. E.g. Salt
(And metallic compounds)
What is the difference between Intermolecular forces and Intramolecular forces?
Inter: (Weaker) The forces holding together billions of molecules together.
Intra: (Very strong) The forces holding the particles of an atom together.
Atoms sometimes join to form …(x)…
X sometimes joins to form …(y)…
x= Molecules
y=Substances
Definition of physical change?
What happens to the molecules when physical change occurs.
What happens to the bonds in the molecule?
A change that does not alter the chemical nature of a substance (the properties stay the same)
The molecules are rearranged so that the appearance of the substance is different.
Intra-molecular bonds don’t break. [Forces holding sub-atomic particles don’t break.]
Inter-molecular bonds do break. [Forces holding millions of molecules together do break.]
Definition of chemical change?
When new substances are made (properties of the product/s are different)
All chemical change is accompanied by a physical change.
What are the spaces between particles of different states?
Particles in a:
SOLID: Strong forces of attraction. Small spaces.
LIQUIDS: Weaker forces than solids, stronger forces than gasses. Bigger spaces than solids, smaller spaces than gasses.
GASSES: Weakest forces, biggest spaces.
All particles are in continual motion, the … the motion the …
The greater the motion the higher the temperature.
Label the movements in different states?
SOLIDS: Vibrational movement only, still stays in the same place.
LIQUIDS and GASSES: Vibrational, translational (moves from place to place) and rotational (spins).
Describe phase change called melting.
Heating objects causing their particles to vibrate faster as the temperature increases. Eventually the particles will break free from their lattices.
The same happens with boiling.
The heat required to cause phase change is called …?
Latent heat
Which type of change, physical or chemical, requires the most amount of energy?
In chemical change: Existing bonds … and new bonds …
Chemical change requires more energy.
Existing bonds break and new bonds are formed.
What are two examples of chemical change?
Decomposition: When there is one reactant and two products.
Synthesis: When there are two reactants and one product.
T/F: There doesn’t have to be equal amounts of mass on both sides of the chemical equation.
False, there has to be an equal amount of atoms and mass on both sides.
This is called Conservation of atoms/mass.
