What is the chemical symbol for oxygen?
Answer : O
Oxygen is represented by the chemical symbol O.
Questions and answers: Physics & Chemistry
Revise Physics & Chemistry: here is a selection of questions of every level, with the answer and an explanation. To test yourself without seeing the answers, play the quizzes.
Play the Physics & Chemistry quizzesVery easy
At what temperature does water boil at sea level, in degrees Celsius?
Answer : 100 °C
Water boils at 100 degrees Celsius at sea level under normal atmospheric pressure.
Which scientist is famous for his theory of gravity after observing an apple fall?
Answer : Isaac Newton
Isaac Newton is associated with the discovery of universal gravitation.
What state of matter is ice?
Answer : Solid
Ice is water in its solid state.
Which force pulls objects toward the center of the Earth?
Answer : Gravity
Gravity is the force that pulls objects toward the center of the Earth.
What is the chemical symbol for iron?
Answer : Fe
Iron is represented by the chemical symbol Fe, from the Latin 'ferrum'.
Which unit measures temperature in the international system?
Answer : The kelvin
The kelvin is the international system unit of temperature, though Celsius is more commonly used.
Which physical phenomenon lets us see a rainbow after rain?
Answer : Refraction of light
The refraction of sunlight through water droplets creates a rainbow.
Easy
What is the approximate speed of light in a vacuum?
Answer : 300,000 km/s
Light travels through a vacuum at approximately 300,000 kilometers per second.
Which scientist discovered natural radioactivity along with her husband Pierre?
Answer : Marie Curie
Marie Curie, with Pierre Curie, discovered radioactivity and isolated polonium and radium.
What is the name of the smallest particle of a chemical element that retains its properties?
Answer : The atom
The atom is the smallest unit of a chemical element that retains its properties.
Which type of chemical reaction releases heat, such as combustion?
Answer : An exothermic reaction
An exothermic reaction releases energy in the form of heat.
Which scale measures the acidity or basicity of a solution?
Answer : The pH scale
The pH scale measures the acidity or basicity of a solution, from 0 to 14.
Which subatomic particle carries a negative electric charge?
Answer : The electron
The electron is a subatomic particle carrying a negative electric charge.
Which instrument measures atmospheric pressure?
Answer : The barometer
The barometer is the instrument used to measure atmospheric pressure.
What is the name of the process by which a liquid turns into a gas?
Answer : Vaporization
Vaporization (or evaporation) is the transition from liquid to gaseous state.
Medium
Which chemical element has the symbol 'Na'?
Answer : Sodium
Sodium has the chemical symbol Na, from the Latin 'natrium'.
Which unit measures the amount of electrical energy consumed?
Answer : The kilowatt-hour
The kilowatt-hour (kWh) measures the amount of electrical energy consumed.
Which physicist formulated the three laws of motion in the 17th century?
Answer : Isaac Newton
Isaac Newton formulated the three fundamental laws of motion in his 'Principia' in 1687.
Which colorless, odorless gas produced by combustion is dangerous because it prevents blood from carrying oxygen?
Answer : Carbon monoxide
Carbon monoxide (CO) is a toxic gas that prevents oxygen transport in the blood.
What is the name of the smallest positively charged particle found in an atom's nucleus?
Answer : The proton
The proton is a positively charged particle found in the atomic nucleus.
Which physical quantity is measured in newtons?
Answer : Force
Force is measured in newtons (N) in the international system of units.
Which type of chemical bond joins atoms by sharing electrons?
Answer : A covalent bond
A covalent bond joins two atoms by sharing one or more pairs of electrons.
Which law states that the pressure of a gas is inversely proportional to its volume at constant temperature?
Answer : Boyle's law
Boyle's law describes the inverse relationship between the pressure and volume of a gas at constant temperature.
Hard
Which quantum mechanics principle states that the position and momentum of a particle cannot both be known precisely at once?
Answer : Heisenberg's uncertainty principle
Heisenberg's uncertainty principle limits the simultaneous precision of a particle's position and momentum.
Which particle, predicted by Peter Higgs, was discovered at CERN in 2012 and gives elementary particles their mass?
Answer : The Higgs boson
The Higgs boson, discovered at CERN in 2012, explains the mechanism that gives elementary particles their mass.
Which law of thermodynamics states that the total entropy of an isolated system can only increase?
Answer : The second law of thermodynamics
The second law of thermodynamics states that the entropy of an isolated system increases or stays constant.
Which Russian chemist created the periodic table of elements in 1869?
Answer : Dmitri Mendeleev
Dmitri Mendeleev created the periodic table of elements in 1869, predicting the existence of then-unknown elements.
Which subatomic particle, discovered in 1932, is electrically neutral and found in the atomic nucleus?
Answer : The neutron
The neutron, discovered by James Chadwick in 1932, is a neutral particle in the atomic nucleus.
Which phenomenon describes the change in perceived frequency of a wave when the source or observer is moving?
Answer : The Doppler effect
The Doppler effect describes the change in perceived wave frequency due to relative motion between source and observer.
Which type of chemical bond results from the transfer of electrons between a metal and a nonmetal?
Answer : An ionic bond
An ionic bond results from the transfer of electrons between a metal atom and a nonmetal atom.
Which physicist formulated the theory of general relativity in 1915?
Answer : Albert Einstein
Albert Einstein published his theory of general relativity in 1915, revolutionizing the understanding of gravitation.
Expert
Which principle states that two identical fermions cannot occupy the same quantum state simultaneously?
Answer : Pauli's exclusion principle
Pauli's exclusion principle states that no two identical fermions can share the same quantum state.
Which equation, formulated by Erwin Schrödinger, describes the time evolution of a quantum system?
Answer : The Schrödinger equation
The Schrödinger equation, formulated in 1926, describes the time evolution of the wave function of a quantum system.
Which French chemist is considered the father of modern chemistry for establishing the law of conservation of mass?
Answer : Antoine Lavoisier
Antoine Lavoisier established the law of conservation of mass and is considered the father of modern chemistry.
Which model describes the atom's structure as a nucleus around which electrons occupy quantized energy levels?
Answer : The Bohr model
The Bohr model, proposed in 1913, describes electrons occupying quantized energy levels around the nucleus.
Which fundamental physical constant relates a photon's energy to its frequency in quantum theory?
Answer : Planck's constant
Planck's constant relates a photon's energy to its frequency in the relation E=hf.
Which quantum phenomenon allows a particle to cross an energy barrier it classically should not be able to overcome?
Answer : Quantum tunneling
Quantum tunneling allows a quantum particle to pass through a potential barrier it could not classically overcome.
Which Danish physicist proposed the principle of complementarity in quantum mechanics?
Answer : Niels Bohr
Niels Bohr proposed the principle of complementarity, stating that quantum objects have complementary properties like wave and particle.
Which chemical reaction, catalyzed by protease-type enzymes, breaks peptide bonds by adding water?
Answer : Hydrolysis
Enzymatic hydrolysis by proteases breaks the peptide bonds of proteins by adding a water molecule.
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