1.
The atomic number of an element is the same as the number of blank found in one atom of the element
Correct Answer
A. Protons
Explanation
The atomic number of an element is defined as the number of protons found in one atom of the element. Protons are positively charged particles located in the nucleus of an atom. The number of protons determines the element's identity and its position on the periodic table. Therefore, the correct answer is protons.
2.
The smallest chemical unit of matter is the
Correct Answer
B. Atom
Explanation
An atom is the smallest chemical unit of matter. It consists of a nucleus, which contains protons and neutrons, and electrons that orbit around the nucleus. Atoms combine to form molecules and compounds. However, an atom itself cannot be broken down into smaller particles without losing its chemical properties. Therefore, it is considered the fundamental building block of matter.
3.
Two or more atoms of different elements can chemically combine to form a
Correct Answer
A. Compound
Explanation
Two or more atoms of different elements can chemically combine to form a compound. In a compound, the atoms are held together by chemical bonds, which can be either ionic or covalent. These bonds result in the formation of a new substance with different properties compared to the individual elements. Compounds can be made up of a variety of elements and can exist in different ratios and arrangements.
4.
Which of the following subatomic particles is not found in the nucleus of an atom
Correct Answer
C. Electron
Explanation
Electrons are not found in the nucleus of an atom. They exist in energy levels outside the nucleus, moving around the positively charged protons. Protons and neutrons are the subatomic particles that make up the nucleus of an atom. Protons carry a positive charge, while neutrons have no charge. Electrons, on the other hand, are negatively charged and are responsible for the chemical behavior of atoms.
5.
When an atom loses an electron it becomes
Correct Answer
B. A cation
Explanation
When an atom loses an electron, it becomes a cation. A cation is a positively charged ion because it now has more protons than electrons. This imbalance in charge creates a positive charge on the atom. An anion, on the other hand, is a negatively charged ion formed when an atom gains electrons. A molecule refers to a group of atoms bonded together, and a compound is a substance made up of two or more different elements chemically bonded together.
6.
Ions with opposite charges are generally held together by
Correct Answer
B. Ionic bonds
Explanation
Ionic bonds are generally formed between ions with opposite charges. In an ionic bond, one atom donates electrons to another atom, resulting in the formation of positive and negative ions. These ions are attracted to each other due to their opposite charges, creating a strong bond. This type of bonding is characteristic of compounds composed of metal and non-metal elements. Covalent bonds involve the sharing of electrons between atoms, while hydrogen bonds are weaker attractions between molecules. Municipal bonds, on the other hand, are financial instruments used by governments to raise funds and are unrelated to chemical bonding.
7.
When pairs of electrons are shared between two atoms the result is a blank bond
Correct Answer
B. Covalent
Explanation
When pairs of electrons are shared between two atoms, the resulting bond is a covalent bond. In a covalent bond, the atoms share electrons in order to achieve a stable electron configuration. This type of bond is typically formed between nonmetal atoms. Ionic bonds, on the other hand, involve the transfer of electrons from one atom to another, resulting in the formation of ions. Hydrogen and carbonic bonds are not valid types of chemical bonds.
8.
Reactions in which food is degraded and energy is released are best termed
Correct Answer
B. Catabolic
Explanation
Catabolic reactions involve the breakdown of complex molecules into simpler ones, releasing energy in the process. This is exactly what happens during the degradation of food, where large molecules such as carbohydrates, proteins, and fats are broken down into smaller molecules like glucose, amino acids, and fatty acids. These reactions release energy that can be used by the body for various cellular processes. Therefore, catabolic is the best term to describe reactions in which food is degraded and energy is released.