1.
Li, Na and K belong to the _________________ family.
Correct Answer
B. Alkali Metals
Explanation
Li, Na, and K belong to the Alkali Metals family because they all have one valence electron in their outermost energy level. This makes them highly reactive and they readily lose this electron to form a positive ion. Alkali Metals are located in Group 1 of the periodic table and are known for their low melting and boiling points, as well as their ability to react vigorously with water.
2.
The atomic number is equal to the number of ________________.
Correct Answer
D. Protons or electrons
Explanation
The atomic number of an element is defined as the number of protons in the nucleus of an atom. Since atoms are electrically neutral, the number of protons is also equal to the number of electrons orbiting the nucleus. Therefore, the correct answer is "protons or electrons" because the atomic number is equal to the number of either protons or electrons in an atom.
3.
If the atomic mass of an element is 12.01 and the atomic number is 6, how many neutrons are in atom of this element?
Correct Answer
B. 6
Explanation
The atomic number of an element represents the number of protons in its nucleus. Since the atomic number is given as 6, we know that the element has 6 protons. The atomic mass of an element represents the sum of its protons and neutrons. In this case, the atomic mass is given as 12.01. Therefore, the number of neutrons can be calculated by subtracting the atomic number from the atomic mass: 12.01 - 6 = 6. Hence, there are 6 neutrons in an atom of this element.
4.
A cation is an ion with a _________________ charge.
Correct Answer
B. Positive
Explanation
A cation is an ion with a positive charge because it has lost one or more electrons, resulting in an excess of protons compared to electrons. This imbalance creates a positive charge, making the cation positively charged.
5.
Electrons in the outermost energy level of an atom are the ______________ electrons.
Correct Answer
B. Valence
Explanation
Valence electrons are the electrons in the outermost energy level of an atom. These electrons are involved in chemical bonding and determine the atom's reactivity and ability to form bonds with other atoms.
6.
As you move down the periodic table in a family the valence electrons do not change.
Correct Answer
A. True
Explanation
As you move down the periodic table in a family, the valence electrons do not change because the number of valence electrons is determined by the group number or the column in which an element is located. Elements in the same group or family have the same number of valence electrons, regardless of their position within the group. Therefore, as you move down the periodic table in a family, the valence electrons remain the same.
7.
As you move across the periodic table from left to right the valence electrons stay the same.
Correct Answer
B. False
Explanation
As you move across the periodic table from left to right, the number of valence electrons does not stay the same. Valence electrons are the electrons in the outermost shell of an atom, and they determine the chemical properties of an element. As you move from left to right across the periodic table, the number of valence electrons increases by one with each element. This is because the number of protons in the nucleus also increases, resulting in a stronger attraction for the outermost electrons. Therefore, the correct answer is false.
8.
In an ionic bond electrons are ________________ when forming a chemical bond.
Correct Answer
A. Transferred
Explanation
In an ionic bond, electrons are transferred from one atom to another when forming a chemical bond. This transfer occurs because one atom has a higher electronegativity and attracts the electrons more strongly than the other atom. As a result, one atom becomes positively charged (cation) as it loses electrons, while the other atom becomes negatively charged (anion) as it gains those electrons. This transfer of electrons creates a strong electrostatic attraction between the oppositely charged ions, forming the ionic bond.
9.
In a covalent bond, electrons are _______________________when forming a chemical bond.
Correct Answer
B. Shared
Explanation
In a covalent bond, electrons are shared when forming a chemical bond. This means that both atoms involved in the bond contribute one or more electrons to a shared electron pair. This sharing allows both atoms to achieve a more stable electron configuration, filling their outermost energy levels. By sharing electrons, the atoms can achieve a more balanced charge distribution and form a stronger bond.
10.
Predict whether the following is an ionic bond or covalent bond.
K (potassium) and I (iodine)
Correct Answer
A. Ionic bond
Explanation
The bond between potassium (K) and iodine (I) is an ionic bond. Ionic bonds occur when there is a complete transfer of electrons from one atom to another, resulting in the formation of ions with opposite charges. In this case, potassium loses one electron to become a positively charged ion (K+), while iodine gains one electron to become a negatively charged ion (I-). The attraction between these oppositely charged ions creates the ionic bond.
11.
Predict whether the following is an ionic bond or covalent bond.
O (oxygen) and O (oxygen)
Correct Answer
B. Covalent bond
Explanation
The given pair of atoms is both oxygen, which is a nonmetal. Nonmetals tend to form covalent bonds, where electrons are shared between the atoms. Therefore, the bond between two oxygen atoms is a covalent bond.
12.
A neutron has a ________________ charge.
Correct Answer
B. Neutral
Explanation
A neutron has a neutral charge because it contains no net electrical charge. It is composed of neutral particles called quarks, specifically two down quarks and one up quark. The charges of these quarks cancel each other out, resulting in a neutral overall charge for the neutron.
13.
The electron is located in _______________.
Correct Answer
B. Electron cloud around nucleus
Explanation
The electron is located in the electron cloud around the nucleus. This is because electrons are negatively charged particles that orbit the positively charged nucleus in an atom. The electron cloud represents the probability distribution of finding an electron at a particular location around the nucleus. It is a region where electrons move in a random and unpredictable manner, forming different energy levels and subshells. Therefore, the correct answer is the electron cloud around the nucleus.
14.
The mass of a proton is over __________________ greater than the mass of an electron.
Correct Answer
B. 1,823 times
Explanation
The mass of a proton is significantly greater than the mass of an electron. In fact, the mass of a proton is over 1,823 times greater than the mass of an electron. This means that a proton is much heavier than an electron.
15.
Covalent bonds form between
Correct Answer
A. Non-metal and non-metal
Explanation
Covalent bonds form between non-metal and non-metal atoms because both non-metal atoms have high electronegativity values and tend to attract electrons towards themselves. In a covalent bond, the non-metal atoms share electrons to complete their outer electron shells and achieve stability. This sharing of electrons allows both atoms to achieve a full outer shell configuration and form a stable molecule. On the other hand, metal and non-metal atoms tend to form ionic bonds, where the metal atom donates electrons to the non-metal atom, resulting in the formation of ions with opposite charges.