The Atomic Revolution
This scientist's experiment showed that most alpha particles passed through gold foil while a small fraction experienced large deflections.
Who is Ernest Rutherford?
This subatomic particle has a -1 charge and a nearly negligible mass.
What is an electron?
The periodic table arranges the elements in order of increasing value of this number.
What is atomic number?
An atom that gains or loses electrons and therefore acquires a net electrical charge is called this.
What is an ion?
Atoms of the same element that contain different numbers of neutrons are called these.
What are isotopes?
This scientist's experiments led to the discovery of the negatively charged electron and the proposal of the plum-pudding model.
Who is J.J. Thomson?
This particle has approximately 1 amu of mass and a +1 charge.
What is a proton?
The vertical columns of the periodic table are called these, and elements within them generally have similar properties.
What are groups or families?
A positively charged ion is called this.
What is a cation?
An atom of chlorine-37 has 17 protons. This is its number of neutrons.
What is 20?
This scientist is credited with the modern organizational system of the periodic table.
Who is Dmitri Mendeleev?
An atom has 13 protons, 14 neutrons, and 13 electrons. Its atomic number and mass number are these.
What are 13 and 27?
Silicon, arsenic, and germanium are examples of elements in this broad classification, whose electrical properties make them useful as semiconductors.
What are metalloids?
A neutral fluorine atom contains 9 electrons. After gaining one electron, it becomes this ion.
What is F^-?
Unlike ordinary isotopes, these isotopes have unstable nuclei and spontaneously undergo nuclear changes.
What are radioactive isotopes?
This ancient Greek philosopher proposed that matter consisted of tiny, indivisible particles called atomos.
Who is Democritus?
An atom contains 20 protons, 20 neutrons, and 18 electrons. Its charge, atomic number, and mass number are these.
What are 2+, 20, and 40?
This group of elements has properties which might be described as unpredictable.
What are the transition elements?
An ion has a charge of 3- and contains 18 electrons. This is the element from which the ion was formed.
What is phosphorus?
An element consists of 75.77% isotope A with a mass of 34.97 amu and 24.23% isotope B with a mass of 36.97 amu. Its average atomic mass is approximately this.
What is 35.45 amu?
John Dalton's atomic theory proposed which three key ideas?
What is all atoms are made of tiny, indestructible particles, all atoms of a given element have the same mass, and all elements combine in fixed ratios to form compounds.
A particle has 35 protons, 45 neutrons, and 36 electrons. Its atomic number, mass number, and charge identify it as this species.
What is 80Br-, the bromide ion?
Hydrogen appears in Group 1A, but does not belong to this family of highly reactive metals.
What are the alkali metals?
Two ions, X^2+ and Y^-, each contain 10 electrons. These are the elements represented by X and Y.
What are magnesium and fluorine?
An element has two isotopes. One has a mass of 63 amu and an abundance of 69%, while the other has a mass of 65 amu. This is the approximate abundance of the second isotope if the element's average atomic mass is 63.6 amu.
What is 31%?