1.
Elements consist of a single type of atom.
Correct Answer
A. True
Explanation
Elements are substances that cannot be broken down into simpler substances by chemical means. Each element is made up of only one type of atom. For example, oxygen is an element that consists of only oxygen atoms, and gold is an element that consists of only gold atoms.
2.
As you move left along with the periodic table, the atomic number of the elements tends to
Correct Answer
B. Decrease
Explanation
As you move left along the periodic table, the atomic number of elements tends to decrease. This is because elements are arranged in increasing order of atomic number from left to right across periods in the periodic table.
3.
Which of the following is NOT an indicator of a Chemical Reaction?
Correct Answer
C. It becomes poisonous.
Explanation
A chemical reaction does not necessarily result in the formation of a poisonous substance. While a chemical reaction can cause changes in color, the formation of gas or bubbles, the release of heat or light, and a change in scent, the production of a poisonous substance is not a universal indicator of a chemical reaction.
4.
Which element of the below is the Bohr-Rutherford diagram above representing?
Correct Answer
A. Neon
Explanation
In the Bohr-Rutherford arrangement of neon, the atom has a nucleus at its center containing 10 protons. Neon has two electron shells, with the first shell holding 2 electrons and the second holding 8 electrons, achieving a stable and complete octet in the outermost shell. This arrangement makes neon an inert gas, as it satisfies the octet rule and is generally unreactive.
5.
An Ionic compound is the result of the bonding of
Correct Answer
C. A metal and a nonmetal
Explanation
An ionic compound forms through the bonding of a metal and a nonmetal. Ionic bonds involve the transfer of electrons from the metal to the nonmetal, resulting in the formation of positively charged cations and negatively charged anions. The electrostatic attraction between these oppositely charged ions forms the ionic compound.
6.
What happens/is likely to happen if the atoms within an element have full valence shells?
Correct Answer
B. They are unlikely to bond with other elements.
Explanation
When the atoms within an element have full valence shells, it means that they have achieved a stable electron configuration. This stability makes it unlikely for these atoms to bond with other elements because they do not need to gain, lose, or share electrons to achieve a more stable configuration.
7.
How many valence electrons does an atom require to have a full shell?
Correct Answer
B. 8
Explanation
An atom requires 8 valence electrons to have a full shell. The octet rule states that atoms tend to gain, lose, or share electrons in order to achieve a stable configuration with 8 electrons in their outermost shell, which is the most stable electron configuration. This is known as achieving a full shell or achieving the noble gas configuration.
8.
Beryllium (Valence electrons: 2) more likely to bond with
Correct Answer
A. Sulfur (Valence electrons: 6)
Explanation
Beryllium is more likely to bond with sulfur because they have a compatible number of valence electrons. Beryllium has 2 valence electrons, while sulfur has 6 valence electrons. In order to achieve a stable electron configuration, beryllium can donate its 2 valence electrons to sulfur, forming an ionic bond. This allows both atoms to achieve a full outer electron shell. Neon, on the other hand, already has a full outer electron shell with 8 valence electrons, so it is less likely to form a bond with beryllium. Neon is also a noble gas; noble gases usually do not bond with other elements.
9.
Which and how many atoms do Hydrogen Peroxide (H2O2) consist of?
Correct Answer
B. Two Hydrogen, Two Oxygen
Explanation
Hydrogen peroxide (H2O2) is a chemical compound composed of two hydrogen (H) atoms and two oxygen (O) atoms. The chemical structure of hydrogen peroxide can be represented as H-O-O-H, illustrating the arrangement of the atoms. The oxygen atoms are connected by a single bond, and each oxygen atom is also bonded to a hydrogen atom. The presence of peroxide linkage (O-O) contributes to the unique properties of hydrogen peroxide, and it is commonly known for its use as a disinfectant and bleach.