Chapter 2 Flashcards
What is matter?
Something that has mass and occupies space
Matter consists of tiny and discrete particles.
What are the three states of matter?
- Solid
- Liquid
- Gas
How can matter be classified?
- Element
- Compound
Define an element.
Substances that only consist of one type of atom, such as pure iron metal.
Define a compound.
Substances that consist of more than one element that form a molecule.
What is an atom?
Smallest and indivisible particles of an element.
What is a molecule?
Compound made up of two or more atoms (different or same kind of atoms).
What is an ion?
Particles that carry charges [cation(+) or anion(-)].
How are particles arranged in a solid?
Packed very closely.
Describe the movement of particles in a liquid.
Move randomly and slowly.
What is the kinetic energy level in gases?
High speed.
Rate of diffusion in solids is:
Low.
What happens during melting?
Solid is heated, particles obtain energy and vibrate at a faster rate.
What is vaporization?
Occurs in two conditions: either evaporation or boiling.
Define freezing.
Temperature drops and heat energy is released, changing liquid to solid.
What is condensation?
A process by which a gas or vapor changes to liquid state at a certain temperature.
What is sublimation?
A process of conversion of a substance from the solid to the vapor state without its becoming liquid.
What occurs at the melting point?
The temperature remains constant as heat energy is used to break the bond.
Describe the arrangement of particles in a solid state.
Very closely packed together in an orderly manner.
What is the relationship between energy produced during bond formation and heat released during cooling?
They are equal during the freezing point transition.
What experiment did Chadwick conduct to discover neutrons?
Bombarded beryllium-9 with alpha particles
This led to the identification of neutrons in the atomic nucleus.
John Dalton
Atoms
JJ Thomson
Electrons
Ernest Rutherford
Protons
