Science Basics
What is a hypothesis?
A possible, testable explanation for one or more observations or a suggested, testable answer to a question.
The smallest chemical unit of an element.
What is an atomic number?
the number of protons in an atom.
What are products?
New substances formed as a result of a chemical change.
What are binary compounds?
Compounds made of only two elements.
What is an inference?
A logical conclusion drawn from observations, previous knowledge, and available information.
What is matter?
Anything that has mass and takes up space.
What is a mass number?
The sum of the protons and neutrons in the nucleus of an atom.
What are reactants?
Substances that undergo a chemical change.
What is a synthesis reaction?
A chemical reaction in which two or more substances react to form a single compound.
What is a scientific theory?
A well-tested explanation of a phenomenon in the natural world.
What is kinetic energy?
The energy of an object has due to its motion.
What is a Valence electron?
Electrons that are in the highest energy level(the energy level farthest from the nucleus) of an atom of an element.
What is the ion?
An atom or a group of atoms that has a positive or negative charge.
What is a decomposition reaction?
A chemical reaction in which a compound breaks down into two or more simpler substances.
What is a variable?
A factor that can change in an experiment.
What is density?
The ratio of a substance's mass to its volume.
Although there are many illustrations and models of atoms, have scientists actually seen atoms themselves?
No.
What is adhesion?
The force of attraction between molecules of different substances so that they tend to stick together.
What is a combustion reaction?
A chemical reaction in which a substance reacts rapidly with oxygen, often producing heat and light.
What is an observation?
The gathering of information using senses or with the aid of instruments.
What is a compound?
A pure substance that contains two or more elements chemically joined in a fixed proportion.
Where is the greatest part of the mass of an atom found?
In the nucles.
What is cohesion?
The force of attraction between molecules of the same substances so that they tend to stay together.
What is chemical energy?