Fundamental Scientific Principles Flashcards

Which phase of matter has a definite volume but no definite shape?

Answer: Liquid

Liquids have a fixed volume but take the shape of their container because their particles can flow past one another.

What does a catalyst do in a chemical reaction?

Answer: Lowers the activation energy without being consumed

A catalyst lowers the activation energy needed for a reaction to proceed and is not permanently consumed in the process.

What is the principle behind a magnetic resonance imaging (MRI) scan?

Answer: Nuclear spin of hydrogen atoms in a magnetic field

MRI exploits the quantum spin of hydrogen nuclei, which align in magnetic fields and emit signals when disturbed by radio waves.

Which law describes the relationship between the pressure and volume of a gas at constant temperature?

Answer: Boyle's Law

Boyle's Law states that at constant temperature, the pressure of a gas is inversely proportional to its volume (P₁V₁ = P₂V₂).

What is the name of the force that opposes the relative motion between two surfaces in contact?

Answer: Friction

Friction is the resistive force that acts parallel to surfaces in contact and opposes their relative motion or tendency to move.

In genetics, what term describes an allele that is only expressed when two copies are present?

Answer: Recessive

A recessive allele is only expressed in the phenotype when an organism carries two copies of it (homozygous recessive).

Which electromagnetic waves have the shortest wavelength?

Answer: Gamma rays

Gamma rays have the shortest wavelengths (below 10 picometers) and therefore the highest energy in the electromagnetic spectrum.