Chemistry: 5.2-5.3 & 6
How many protons and electrons are present in Al3+?
13 p+ & 10 e- (Aluminum has 13 protons and 13 electrons. When the cation is formed, three electrons are lost. Thus, the correct number of electrons becomes 10. The aluminum ion has 13 protons and 10 electrons.)
How many protons are present in Ba2+?
56
How many protons are present in Ba2+?
Although the atom loses electrons to form a positive ion, the number of protons does not change. Barium atoms and ions always have 56 protons.
Atomic Radius are larger________ .
Atoms are larger at the bottom of the periodic table and on the left side of the periodic table. The size of an atom increases as you go from right to left across a period and from top to bottom down a group.
Why are both hydrogen and cesium s-block elements, when hydrogen has one electron and cesium has 55?
Blocks of elements on the periodic table are based only on an element's valence electrons.
Which of the following elements is most likely to form a negatively-charged ion? a. Cl b. Br c. F d. I
C. Fluorine (F)
Which of the following have the same number of electrons? Cl-, O2-, F, Ca2+, Fe3+
Ca2+ and Cl- both have 18 electrons
Which element has the lowest first ionization energy? a. Li b. Na c. K d. Cs
Cesium (Cs). It is located at the bottom left portion of the periodic table, and thus, has the lowest first ionization energy.
The downward movement of electrons between discreet energy releases energy in the form of light. This light is emitted from the atom and is called an __________.
Emission
When an atom loses energy by electron transition, a(n) _____________ is produced.
Emission
The total number of electrons in s orbitals in a germanium atom is ________.
Germanium is in period 4. This element has s-electrons in the first, second, third, and fourth periods. Because each s orbital contains two electrons, there are a total of 8 electrons.
Why was Mendeleev's periodic table widely accepted?
He predicted the existence and properties of undiscovered elements. (There is a periodic repetition of chemical and physical properties of elements when they are arranged by increasing atomic number.)
Ionization Energy
Ionization energy is the energy required to remove an electron from a gaseous atom. An atom that has a large ionization energy would require a large amount of energy to remove an electron and form a positive ion.
The Heisenberg uncertainty principle states that ____________.
It is impossible to simultaneously know the precise position and the velocity of a particle.
In what part of the periodic table would you expect to find an element that emits light when struck by electrons?
Lanthanides are part of the inner transition metals.
Atoms with large ionization energy values are __________.
Less likely to form positive ions
Atoms that lose electrons to form positive ions are __________.
M E T A L S. They will lose electrons to form positive ions.
In general, when comparing ions to their atoms, what trend is observed?
Positive ions are smaller and negative ions are larger than their corresponding atoms. (Cations are always smaller than their atoms. Anions are always larger than their atoms.)
The minimum amount of energy that can be gained or lost by an electron is a _________.
Quantum
The ionic compound, sodium chloride, is formed from atoms of the elements sodium and chlorine. What happens to the size of each atom when it forms an ion?
Sodium decreases in size and chlorine increases in size. (The sodium ion is a cation, so it is smaller than its atom. The chlorine is an anion, so it is larger than its atom.)
T or F : "All s orbitals are spherically shaped."
T R U E---The first energy level has only one orbital type(the s orbital. The s orbital is always spherically shaped.
In the periodic table, the principal quantum number corresponds to the ________.
The Period number.
The valence orbitals in an atom are the ___________.
The covalent bonds are formed from the sharing of the outermost electrons. The valence electrons are the O U T E R M O S T electrons in an atom.
Which of the following elements is most likely to form a negatively-charged ion? a. I b. Br c. Cl d. F
The element that is most likely to form an anion will be in group 7A in the upper right portion of the periodic table. F L U O R I N E (F) has the greatest electron affinity and is most likely to form a negative ion.
The ground state of hydrogen corresponds to the _________.
The first energy level corresponds to the ground state (the lowest energy state).
How would you classify an element that has an electron configuration of [Kr]5s24d105p5?
The valence level has electrons in the s and p orbitals. The group A elements are collectively known as the R E P R E S E N T A T I V E elements.
Which atom or ion has 16 protons and 18 electrons? a. S2- b. Ne2+ c. F- d. N+
a. S2- (The atom that has 16 protons is sulfur. An atom of sulfur has 16 electrons. When two electrons are added, the sulfur becomes sulfide — an anion with a 2- charge. Sulfide is represented as S2-.)
Which of the following is an ion? a. O2- b. C c. HCl d. lithium-3
a.O2-
The concept that all moving particles have wave characteristics is attributed to ___________.
de Broglie
What is the name for the amount of energy required to remove an electron from an atom?
ionization energy
