Introduction to Modern Physics

These flashcards cover fundamental concepts of modern physics including atomic theory, particle physics, and the principles of relativity.

Who first suggested the existence of atoms?

Democritus

What did Dalton determine about atoms?

Atoms are distinguished by their masses and can be combined to produce compound molecules.

What is Thomson's model of the atom called?

Plum pudding model.

What is Rutherford's nuclear model of the atom characterized by?

All positive charge and most mass concentrated in a tiny central nucleus, with electrons orbiting at the edge.

What did Bohr's model of the atom limit?

Electrons to certain fixed energy orbits.

What experimental result did Rutherford's gold foil experiment demonstrate?

Most of the atom is empty space.

What conclusion can be drawn from the deflection of alpha particles in Rutherford's gold foil experiment?

All the positive charge inside the atom is concentrated and not uniformly distributed.

What is the charge of an electron?

-1.6 x 10^-19 C.

What is the charge of a proton?

+1.6 x 10^-19 C.

What phenomenon is referred to by the equation E=mc^2?

Matter and energy are interconvertible.

How much energy can be created from a mass equal to that of an electron?

0.51 MeV.

What is the Standard Model of particle physics?

A comprehensive explanation of fundamental particles and their interactions, excluding gravity.

What are the three generations of quarks?

First generation: Up and Down; Second generation: Strange and Charm; Third generation: Top and Bottom.

What defines the baryon number of a baryon?

Every baryon has a baryon number of +1, and every anti-baryon has a baryon number of -1.

What is strangeness in quarks?

Strangeness of a strange quark is -1, while for anti-strange it's +1.

What is pair production?

The creation of a subatomic particle and its antiparticle from a neutral packet of energy, often a photon creating an electron–positron pair.

What happens during annihilation between an electron and a positron?

They collide and release energy as gamma rays.

What role does the de Broglie wavelength play in particle physics?

It relates the wave properties of particles to their momentum.

What key concept is illustrated by Einstein’s theory of relativity?

Length, mass, and time are relative quantities.