Chemistry Midterm study guide
Which of the following correctly completes the statement? Chlorine ____ valance electrons, and the effective nuclear charge, Z, for the chlorine atom shown is ____.
7;7+
With the exception of He, how many valence electrons do noble gases have?
8
Which list arranges the elements Na, Li, K, Rb, and Cs in order of increasing ionization energy (from left to right)?
Cs; Rb; K; Na; Li
The list identifies various properties of four elements: Element 1 is a gas at room temperature Element 2 is a solid which conducts electricity Element 3 is a gas with an effective nuclear charge of +7 Element 4 is malleable and can take the form of a shiny solid sheet.
Elements 2 and 4
How are ionic bonds formed?
Ionic bonds form between metals and nonmetals. This attraction between a positive and negative in forms the ionic bond.
Lithium is in Group 1A, Period 2 of the periodic table. Which statement describes the charge of the ion it typically forms?
It forms a cation with a +1 charge.
To help finalize her decision, the scientist places the elements in order of greatest to least electron affinity. She knows she needs an element with a strong electron affinity. Which answer correctly lists the element with the smallest electron affinity first and the element with the greatest electron affinity last?
Rubidium, calcium, magnesium, oxygen, fluorine
Which arrangement of the following Period 5 elements, from left to right, orders them with respect to their atomic size, from smallest to largest?
Te; Sb; In; Sr; Rb
A mystery has 18 protons. Which one of the following statements is true about the element?
The element belongs in row 3 of the periodic table and is classified as a noble gas.
The periodic law states that:
The properties of elements recur periodically when arranged by increasing atomic number.
Which of the following statements are true once the sodium chloride bond formation shown in the figure takes place?
The resulting sodium cation has a stable octet in its valance. The resulting chlorine anion octet in its valance shell. The electrostatic attraction between the positive ion and negative chlorine forms an ionic bond.
Which of the following statements about the shielding effect and effective nuclear charge are true?
The shielding effect describes how the repulsive forces between electrons work to reduce the amount of attractive force between electrons. The actual attraction felt by the electrons farthest from the nucleus is less than the numerical value based on Coulomb's law. Inner core electrons always shield valance electrons.
Which statements are true concerning elements in the same group of the periodic table?
They have similar periodic properties. They have the same outer shell electron configuration.
An atom X has three electrons in its outermost shell. Which ion will most likely be formed by X?
X^3+
Oxygen Calcium Potassium Nitrogen
anion cation cation anion
The octet rule states that atoms tend to form bonds so that each atom has eight _____ in its ______ shell.
electrons; valence
Which characteristics is not a periodic trend?
number of elements In a group
A sodium atom has ____ valance electron(s). A chlorine atom has ____ valance electron(s).
one ; seven
A chemist is working with a company that produces novel inserts to adjust the flame of a bonfire. She is testing which element is needed to react with sodium and produce a vibrant yellow flame. Se decides to organize the possible reactants using the periodic table base on their properties. The reactant options are calcium, magnesium, flourine, rubidium, and oxygen. The chemist is required to find an element that has the same number of valance electrons as sulfur. Select the element that the chemist chose and an explanation for that choice. Select all that apply.
oxygen, it is in the same group as sulfur
Which pair of words correctly completes the statement? Alkali metals are highly ____ since they ____ easily form ions.
reactive; lose 1 electron
The valance electrons of an atom do not experience the full attractive force of protons in the atom's nucleus due to the presence of inner core electrons. The reduction in nuclear charge experienced by valance electrons due to inner core electrons is called the;
shielding effect
