Atoms and Molecules (552)
What is an element
substance that cannot be broken down into other substances
The temperature at which a solid becomes a liquid
melting point
What is energy?
Describe Newton's first law of motion?
an object at rest will stay at rest until a force acts upon it and an object in motion will stay in motion until a force acts upon it
As the distance between two magnets increases (they get farther apart), what happens to the force between them?
decreases
Name the subatomic particles
protons, neutrons, electrons
The temperature at which a liquid becomes a gas
boiling point
What is work?
whenever a force is applied to an object to set it in motion
Describe Newton's second law of motion
the acceleration of an object depends on its mass and the force acting upon it
What are the two poles on a magnet?
north and south
All matter can be classified into what 3 things?
elements, compounds, mixtures
The temperature at which a gas becomes a liquid
condensation point
What are potential and kinetic energy?
potential - in an object based on its position; kinetic - an object when it moves
Describe Newton's third law of motion
for every action, there is an equal and opposite reaction
A material through which electrons do NOT flow easily is a what?
insulator
What is the difference between a covalent bond and an ionic bond?
covalent bond - atoms share a pair of electrons; ionic bond - atoms gain or lose electrons
What is the difference between a solid and a liquid?
solids have definite shapes and volumes while a liquid has a definite volume but not a definite shape
Name 4 types of energy and give examples of its use
heat - boil water; light - photosynthesis; electrical - light bulbs; chemical - food we eat; nuclear - create electricity; mechanical - fan
What is the difference between speed and velocity
speed - the rate at which an object moves; velocity - an objects speed in a particular direction
Earth's magnetic field is produced by what?
iron core
Name 3 common compounds that you use everyday and their chemical formula
e.g., salt (NaCl), water (H2O), carbon dioxide (CO2)
Name a common solution that is found everywhere on earth and another common solution that is found on 70% of the earth?
air (oxygen and nitrogen) and oceans (salt and water)
What does Einstein's equation E=mc2 express?
the relationship between energy and mass
What is the relationship between momentum, force and mass?
momentum = force X mass
an electric current