Atomic Structure
Which two subatomic particles are found in the nucleus of an atom?
Protons and neutrons
What are the horizontal rows on the periodic table called?
Periods.
What are the electrons in the outermost occupied energy level called?
Valence electrons.
What type of chemical bond forms when two nonmetal atoms share electrons?
A covalent bond.
What pH value represents a neutral solution?
pH 7.
Which subatomic particle determines the identity of an element?
The proton. The number of protons is the atomic number.
What are the vertical columns of the periodic table called?
Groups or families.
How many electrons does a Group 1 metal usually lose, and what charge does it form?
It loses one electron and forms a +1 ion.
What type of bond forms when electrons are transferred from a metal to a nonmetal?
An ionic bond.
A substance turns blue litmus paper red. Is it an acid or a base?
An acid.
Carbon-12 and carbon-14 have the same number of protons but different numbers of neutrons. What are these atoms called?
Isotopes.
What is the name of the family in Group 17?
The halogens.
Oxygen is in Group 16. What charge does it usually form when it gains electrons?
−2, because it gains two electrons.
Which type of bonding involves positive metal ions surrounded by a sea of mobile electrons?
Metallic bonding.
A solution has a pH of 12. How is it classified?
Strongly basic on the pH scale.
An oxygen atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have?
8 neutrons (16 − 8 = 8)
Silicon is located along the stair-step boundary and has properties of both metals and nonmetals. How is it classified?
A metalloid.
Why are metals such as copper good conductors of electricity?
They contain mobile electrons that move through the metallic lattice and carry electrical charge.
Carbon and oxygen are both nonmetals. What type of bond would you expect between them, and why?
Covalent, because nonmetal atoms share electrons.
What two products are formed when an acid and a base undergo a neutralisation reaction?
Salt and water.
An atom has 12 protons and 10 electrons. What is its overall charge, and how did it become charged?
+2. It lost two electrons, forming a positive ion.
Two elements are in the same group, but one is in Period 2 and the other is in Period 3. Which generally has more occupied electron shells, and why?
The Period 3 element, because the period number indicates the number of occupied energy levels for main-group elements.
Why does atomic size generally decrease from left to right across a period?
The number of protons increases while electrons occupy the same main energy level, so the stronger nuclear attraction pulls electrons closer.
Why does solid sodium chloride (NaCl) not conduct electricity, but melted sodium chloride does?
In solid NaCl the ions are fixed in a crystal lattice. When melted, the ions can move and carry electrical charge.
A student adds acid to a piece of chalk and sees bubbles. What gas is being produced, and what additional test could help confirm the solution is acidic?
Carbon dioxide (COâ‚‚). Use a pH meter or an acid-base indicator to confirm acidity.