Module 1 (Synthesis Of Elements Seconds After Big Bang An Flashcards
X-rays in December 1895 after seven weeks of assiduous work during which he had studied the properties of this new type of radiation able to go through screens of notable thickness. He named them X-rays to underline the fact that their nature was unknown.
Wilhelm Conrad Röntgen
accidentally discovered spon- taneous radiation when he placed uranium salts along with photographic plates in a drawer.
Antoine Henri Becquerel
She discovered polonium and radium, championed the use of radiation in medicine and fundamentally changed understanding of radioactivity. our
Marie Curie
All matter is made up of atoms.
The word atom comes from the Greek word “_____” which means _____
Atomos, Indivisible
The idea of the atom evolved from a tiny indivisible sphere into a tiny particle that has a dense core called the ______ where ______ and _____ found
Nucleus, Protons, Neutrons
Surrounding the nucleus are
Electrons
is equal to the number of protons in an atom
atomic number, subscript A,
is equal to the sum of the number of protons and number of neutrons.
atomic mass, superscript Z
is the spontaneous release of energy and particles from the nucleus of an atom. This would only mean that an atom should undergo nuclear transformation.
Radioactivity
is a change in the nuclei of an atom through radioactive decay or through the reaction with another type of nuclei or with a neutron.
Nuclear transformation
are the ones that undergo nuclear transformation.
Unstable atoms
Nuclear transformation could be
nuclear fission, nuclear fusion and radioactive decay.
the nucleus of a heavy atom will separate into two or more light nuclei. may be induced by bombarding it with a neutron as shown in the figure. It can also occur spontaneously.
Nuclear fission
is a process where two or more nucleus of a light atom combine to form a heavy nucleus. Synthesis of elements in the stars is a nuclear fusion process
Nuclear fusion
is a spontaneous process of nuclear transformation that accompanies radiation of alpha, beta or gamma.
Radioactive decay
involves the ejection of two neutrons and two protons. This process stabilizes the atom.
Alpha Decay
why helium atom is found in the product side of an alpha decay equation?
It is because an alpha particle is a helium-like particle.
involves the ejection of a high-speed electron or beta particle. The beta particle ejected might be a negative beta particle or a positive beta particle called positron.
Beta decay
involves the emission of gamma rays which are high energy and high frequency rays. It is the only radiation type involved in nuclear transformation that is not a particle rather it is an electromagnetic form of energy.
Gamma Decay
paved the way of the idea of a tiny, indivisible atom
Democritus and Leucippus
The characteristics are atomic number and atomic maes. They are often written along with the symbol of the name of the element celled an
isotopic notation
Because of the discovery made by _____ we now came to learn that inside the nucleus are protons and neutrons
Chadwick and Goldstein
The beta particle ejected might be a negative beta particle or a positive beta particle called .
positron
is the only radiation type involved in nuclear transformation that is not a particle rather it is an electromagnetic form of energy. Almost all alpha and beta decay is accompanied by gamtna radiation.
Gamma ray
states that the universe started as a small dense hot matter that undergoes inflation.
big bang theory
A star is any massive celestial bodies of _____mostly (Hydrogen and Helium) that produces heat and light due to nuclear fusion going on in its core.
Plasma
All stars are formed in a _____ which is a cloud of gas and dust
nebula
in a process of creating a new atomic nucleus from pre existing nucleons
Nucleosynthesis
The first step of nucleosynthesis is the
_______. It took place seconds after the big bang when the universe had already expanded tremendously that the temperature drops down which allows the formation of neutrons, electrons, and protons.
Big bang nucleosynthesis
The first element produced more than 1 second after the big bang is _____ an isotope of hydrogen
deuterium
a French chemist, first attempted so arrange the known elements in 1789 based on their properties na gasses, metals, nonmetals and eartha.
Antoine Lavoisier
Arranged elements into sets of three called Triads based on their chemical properties.
Johann Dobereiner 1829
Arranged elements into sets of eight called ocataves based on similar properties
John newlands
Arranged elements in order of increasing atomic weights and into sets of eight bound on their physical properties
Dmitri Mendeleev
Arranged elements in order of increasing atomic weights and into sets of eight bound on their physical properties 1870
Lothar meyer
Aminged elementa in order of inccensing atomic number and inte sets of eight.
Aminged elementa in order of inccensing atomic number and inte sets of eight.
Thomson discovered electrons (which he called ‘corpuscles) in atoms in 1897, for which he won a Nobel Prize. He subsequently produced the “plum pudding model of the atom. It shows the atom as composed of electrons scattered throughout a spherical cloud of positive charge.
J. J thomson
drew upon the Ancient Greek idea of atoms (the word atomcomes from the Greek “atomos meaning indivisible) His theory stated that atoms are indivisible, those of a given element are identical, and compounds are combinations of different types of atoms
John dalton (1803)
modified Rutherford’s model of the atom by stating that electrons moved around the nucleus in orbits of fixed sizes and energies. Electron energy in this model was quantised, electrons could not occupy values of energy between the fixed energy levels.
NIELS BOHR
1913
stated that electrons do not move in sat paths around the nucleus, but in waves. It is impossible to know the exact location of the electrons, instead, we have clouds of probability’ called orbitals, in which we are more Sikely to find an electron.
ERWIN SCHRÖDINGER
