Chemical Bonds Review Quiz

NaCl is the chemical formula for sodium chloride. Sodium chloride is a compound made up of sodium (Na) and chloride (Cl) ions. It is commonly known as table salt and is used in cooking and food preservation. Sodium chloride is a white crystalline solid that is highly soluble in water and has a salty taste. It is essential for maintaining fluid balance in the body and is also used in various industries such as chemical, pharmaceutical, and manufacturing.

True, a chemical bond occurs when atoms lose, gain, or share electrons. This statement is true because chemical bonding involves the interaction between atoms, where they either transfer or share electrons to achieve a stable electron configuration. In ionic bonding, atoms lose or gain electrons to form ions, while in covalent bonding, atoms share electrons to complete their outer electron shells. Therefore, the statement accurately describes the concept of chemical bonding.

True, compounds containing polyatomic ions can have both ionic and covalent bonds because polyatomic ions are groups of atoms that are covalently bonded together, but as a whole, they carry a net charge and behave as a single unit in ionic compounds. The covalent bonds within the polyatomic ion hold the atoms together, while the ionic bond is formed between the polyatomic ion and other ions in the compound. This dual nature of bonding allows compounds with polyatomic ions to have characteristics of both ionic and covalent compounds.

In a covalent bond, electrons are shared between two atoms. This means that both atoms contribute electrons to the bond, creating a stable arrangement. This sharing of electrons allows both atoms to achieve a full outer electron shell, resulting in a more stable and lower energy state.

The iodine ion (1-) carries a negative charge. This is because it has gained one electron, resulting in an excess of negatively charged particles compared to positively charged particles. Therefore, the overall charge of the iodine ion is negative.

True, compounds have properties unlike those of the elements because compounds are formed by the combination of two or more elements in fixed ratios, resulting in a new substance with different chemical and physical properties. This is due to the rearrangement of atoms and the formation of new chemical bonds in compounds, which leads to unique characteristics that are distinct from the individual elements. Therefore, it is true that compounds have properties unlike those of the elements.

True, covalent bonding occurs when atoms share electrons to form a stable molecule. In this type of bonding, neutral particles called molecules are formed. Therefore, the statement that neutral particles formed as a result of covalent bonding are called molecules is true.

Binary compounds are composed of two atoms. This is because binary compounds are formed when two different elements combine chemically. Each element contributes one atom to the compound, resulting in a total of two atoms. Therefore, the correct answer is "two".

True, when writing the formula of a compound, the symbol of the element with the positive oxidation number comes first. This is because in a compound, the element with the positive oxidation number is usually the cation, which is written first in the formula. The cation is the element that loses electrons and has a positive charge. Therefore, it is convention to write the symbol of the element with the positive oxidation number first in the formula.

True, a subscript in a chemical formula is a number written below and to the right of an element's symbol, indicating the number of atoms of that element present in a unit of the compound. This is a fundamental concept in chemistry as it allows us to determine the ratio of different elements in a compound and understand its composition. Therefore, the statement that a subscript tells how many atoms of an element are in a unit of a compound is true.

When an atom's outer energy levels are not filled completely, the atom can gain, lose, or share electrons. This is because atoms with incomplete outer energy levels are typically unstable and seek to achieve a more stable configuration. They can do this by either gaining, losing, or sharing electrons with other atoms to complete their outer energy levels and achieve a more stable electron configuration. This process allows atoms to form compounds and participate in chemical reactions.

Compounds that are hydrates contain water as an ingredient. Hydrates are compounds that have water molecules trapped within their crystal structure. These water molecules are known as water of hydration. The presence of water in hydrates can affect their physical and chemical properties, such as solubility and stability. Therefore, the correct answer is water.

Hydrogen is the atom that contains the fewest electrons. It has only one electron in its outermost shell, making it the atom with the lowest number of electrons. Water, oxygen, and helium all have more than one electron in their outermost shells, so they contain more electrons than hydrogen.

False, a covalent bond is the bond that forms between atoms when they share electrons.

False, each noble gas has an outer energy level that is completely filled, these elements do not form chemical bonds easily.

Carbon monoxide (CO) is a compound composed of one carbon atom and one oxygen atom, while carbon dioxide (CO2) is composed of one carbon atom and two oxygen atoms. Therefore, the difference between carbon monoxide and carbon dioxide lies in the number of oxygen atoms present in each compound.

When elements form bonds, it changes their chemical and physical properties. This is because bonding involves the sharing, transfer, or redistribution of electrons between atoms, which can result in changes in the arrangement and behavior of the atoms. These changes can affect various properties of the elements, such as their reactivity, stability, melting point, boiling point, conductivity, and so on. Therefore, the formation of bonds leads to alterations in both the chemical and physical characteristics of the elements involved.

The oxidation number for an ion is always the same as the charge on the ion. This is because the oxidation number represents the number of electrons gained or lost by an atom when it forms an ion. The charge on the ion is determined by the gain or loss of electrons, so the oxidation number must be equal to the charge.

Francium belongs to the same chemical family as sodium, which is the alkali metals group. Alkali metals are known to have a tendency to lose one electron and form a positive charge. Therefore, Francium, being in the same family, will also carry a positive charge.

An ionic compound carries a neutral charge because it is formed by the transfer of electrons between a metal and a non-metal. The metal loses electrons to become positively charged (cation), while the non-metal gains those electrons to become negatively charged (anion). The positive and negative charges balance each other out, resulting in an overall neutral charge for the compound.

Chemical compounds are more stable than their individual elements because they are formed through chemical bonding, which involves the sharing or transfer of electrons. This bonding creates a more stable arrangement of atoms, allowing the compound to have lower energy and greater stability compared to the individual elements. The formation of chemical compounds often involves the attainment of a full outer electron shell, which is energetically favorable. Therefore, chemical compounds tend to be more stable than their constituent elements.

Noble gases are known for their stability and low reactivity due to their full outer electron shells. This means that they have no tendency to gain, lose, or share electrons with other elements, making them unreactive. Therefore, noble gases do not react with anything, hence the correct answer is "nothing".

False, an element that loses electrons when bonding with other atoms has a positive oxidation number.