Week 0 basics revision Flashcards
What is a superoxide anion?
An oxygen molecule with an additional electron: O2 + e- → O2-
How do you write the Na cation equation?
Na → Na+ + e-
What is the definition of a compound?
Two or more elements in a definite and unchanging proportion - a substance containing two or more elements.
What is the name of a positively charge ion?
A cation.
What is the name of a negatively charge ion?
An anion.
What is an ionic compound?
An array of ions, not individial molecules. E.g. NaCl consists of Na+ and Cl- ions.
What are two major laws of chemistry?
The law of conservation of mass and the law of definite proportion. I.e. In a given chemical compound, the elements are always combine in the same proportions by mass, and chemical reaction cannot cause the loss or gain of mass.
What is the law of multiple proportions?
Whenever two elements can form more than one compound, the different masses of one element that combines with the same mass of the other element are in the ratio of small whole numbers.
Eg: sulpher dioxide SO2: 1 x S, 2 x O, ratio 1:2
Sulpher trioxide SO3: 1 x S, 3 x O, ration 1:3
What is the mass of an electron?
9.09x10-31kg or 5.4858x10-4u
What determines the species of an atom?
The number of protons it has.
What is the mass of a neutron
1.6749 x 10-27kg or 1.0087u
What is the mass of a proton?
1.6726 x 10-27kg or 1.0073u
What is the charge of an electron?
-1.6022 x 10-19 C
What is the charge of a proton?
+1.6022 x 10-19 C
What is the symbol for an atom’s mass number? What does ‘mass number’ mean?
A. The number of protons and neutrons in the nucleus. This indicates what isotope it is.
An atom’s given atomic mass number is the average of masses of naturally occurring isotopes.
What is the symbol for an atom’s atomic number? What does ‘atomic number’ mean?
Z. How many protons (only) the nucleus contains. This indicates what species (element) the atom is.
What is an isotope?
Atoms of an element with a different number of neutrons. E.g.
What particles are neutrons and protons, but not electrons, made up of?
Quarks.
What does it mean if an atom is radioactive?
The nucleus is unstable and undergoes spontaneous decay.
What is a nuclide?
A nuclide (or nucleide, from nucleus, also known as nuclear species) is an atomic species characterized by the specific constitution of its nucleus, i.e., by its number of protons, Z, its number of neutrons, N, and its nuclear energy state.
What is the term for an atomic species characterized by the specific constitution of its nucleus, i.e., by its number of protons, Z, its number of neutrons, N, and its nuclear energy state.
Nuclide.
What is a radionuclide?
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is an atom that has excess nuclear energy, making it unstable.
What does the symbol u stand for?
The dalton or unified atomic mass unit (symbols: Da or u) is defined as 1/12 of the mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state and at rest. The atomic mass constant, denoted mu, is defined identically, giving mu = m(12C)/12 = 1 Da
It is equal to 1.66054 x 10-27kg
or 1/12th the mass of 1 atom of 12C
