Ch03_outline_-_Tagged

What did Antoine Lavoisier demonstrate in 1772 regarding matter and transformations?

He showed that the total amount of substances before and after transformations remains the same: 'Nothing is lost, nothing is created, everything is transformed.'

What is matter?

Anything that takes up space and has mass.

What is an element?

A substance that cannot be broken down into other substances.

What is an atom?

The smallest unit of an element that retains the characteristics of that element.

What is the charge of a proton?

Positively charged.

What occurs when the number of protons equals the number of electrons in an atom?

The atom is electrically neutral.

What is an ion?

A charged atom due to lost or gained electrons.

What is an isotope?

An atom of an element with a different number of neutrons.

What is conservation of mass?

Matter cannot be created or destroyed; it simply changes form.

What is a chemical bond?

The force that holds atoms together in molecules.

What is an ionic bond?

A very strong bond that forms when one atom donates its electrons to another atom.

What is a covalent bond?

A bond that forms when pairs of atoms share electrons.

What does the pH scale indicate?

The strength of acid and base solutions.

What is a phase change?

A change in matter from one state (solid, liquid, or gas) to another, without a change in chemical composition.

What is kinetic energy?

Energy associated with motion.

What is potential energy?

Energy that is stored and has not yet been released.

What does the first law of thermodynamics state?

Energy cannot be created or destroyed, but can change forms.

What is meant by entropy?

A measure of disorder in a system; it increases without energy input.

What is the 10% law in ecological terms?

Only about 10% of energy is transferred from one trophic level to the next.

What do primary producers do in an ecosystem?

They transform sunlight into chemical energy through photosynthesis.

What role do decomposers play in a food chain?

They feed on dead organisms and recycle nutrients back into the ecosystem.

What is geothermal energy?

Energy that comes from the Earth's core.

What is hydrogen bonding?

A weak bond that forms when a hydrogen atom is attracted to an atom with a negative charge.