PHYSICS: ATOMIC STRUCTURE

Activity The number of nuclei of a sample that decay per second. Its unit is the becquerel, Bq Alpha decay A type of radiactive decay in which an alpha particle is given out from a decaying nucleus Alpha particle A positively charge particle made up of two protons and two Read more…

Atomic Structure key terms

Dalton’s theory He composed the theory that all matter is composed of extremely small particles called atoms, that cannot be divided Thomson’s model He came up with the model in which atoms were made up of positively charged substances with negatively charged electrons scattered about. Also called the “plum pudding Read more…

Unit #1-Atomic Structure

Atomos greek word for atom- means not able to be divided Democritus Greek philosopher who developed an atomistic theory of matter (460-370 BC) atom (physics and chemistry) the smallest component of an element having the chemical properties of the element Dalton’s Atomic Theory 1) elements are composed of atoms. 2) Read more…

Chapter 30 : Nuclear Physics

Atomic number Z, of an atom is the number of protons. (Nuclear charge= Ze Atomic Mass Unit 1.66 X 10^-27 Kg (u) Mass number (A) number of neutrons and protons. Nuclear mass= A (u) Nuclide nucleus of an isotope. Strong nuclear force also called strong force, acts between protons and Read more…

Chapter 9 – Atomic Physics

Atoms The smallest particle of an element that can enter into a chemical combo Electrons Negatively charged subatomic particles Quantum A discrete amount “packet” Photoelectric effect The emission of electrons that occurs when certain metals are exposed to light. Photon A “particle” of electromagnetic energy Dual nature of light Light Read more…

Physics atomic structure of matter

Fnet*t=mv-mv0 law of impulse and momentum Vector Impulse V or S Vector Momentum V or S Kgm/s or N*s SI units for Impulse and Momentum Momentum Sum of individual momenta Conserved Total momentum is m1v1+m2v2=m1v1’+m2v2′ Law of elastic collision m1v1+m2v2=v'(m1+m2) Law of inelastic collision m1v1’=m2v2′ Law when both objects have Read more…

Physics: Atomic structure

Atom The smallest quantity of an element that can take part in a chemical reaction, consisting of a positively charged nucleus made up of protons and neutrons, surrounded by negatively charged electrons Nucleus The positively charged, dense region at the centre of an atom, made up of protons and neutrons, Read more…

Year 12 Atomic Physics

Absorber Material that prevent radioactive emission from passing through it. ? Activity Number of radioactive emissions/counts per second- also known as “rate of decay”. ? Alpha emission Release of alpha particle from, unstable nucleus (A 2+ helium ion or a helium nucleus. ? Alpha particle The nucleus of a helium Read more…

The Atom and Nuclear Physics

Who believed the atom was a solid sphere? Democritus What 3 things did Democritus propose about the atom? – Matter can not be divided , cannot be cut(atomos) – Small hard particles, that are made of the same material but are different shapes and sizes – They are always moving Read more…

Chapter 21 Atomic Physics

What is blackbody radiation? electromagnetic waves reflected off a blackbody What is a blackbody? object that has absorbed almost all electromagnetic waves What is an example of a blackbody? black hole What is ultraviolet catastrophe? failed prediction of classical physics that the energy radiated by a blackbody at extremely short Read more…

Ch. 13: Atomic & Nuclear Physics

Introduction Light it wave-like. Photoelectric Effect Light shining on various metal surfaces cause electrons to be ejected from the surfaces. Birth of Quantum Theory Developed in 20th century by Mark Planck. Energy only occurs in small amounts called quanta. (Explains nuclear and radiaiton phenomena). E=hf-W Wave-Particle Duality The concept that Read more…