Cell Biology & Genetics - Principles Of Cellular Life

Hydrophilic substances have an affinity for water and can easily dissolve in it. On the other hand, hydrophobic substances repel water and do not dissolve in it. Therefore, it is true that hydrophilic substances dissolve easily in water while hydrophobic substances do not.

Polar covalent bonds occur when the electrons in a bond are not shared equally between the atoms involved. This happens when there is a difference in electronegativity, which is the ability of an atom to attract electrons towards itself. If the electronegativity difference between the atoms is small, a polar covalent bond can form. Therefore, the given statement is true.

Mrs. Salvador is correct. pH is indeed a measure of the number of hydrogen ions in a solution. It is a scale that ranges from 0 to 14, with 0 being highly acidic, 7 being neutral, and 14 being highly alkaline. The pH value indicates the acidity or alkalinity of a solution based on the concentration of hydrogen ions present. Therefore, the statement is true.

Atoms with vacancies can form chemical bonds. Chemical bonds connect atoms into molecules.

Acids are substances that release hydrogen ions (H+) when dissolved in water, while bases are substances that accept hydrogen ions. This statement is true because it accurately describes the behavior of acids and bases. Acids donate H+ ions, which increases the concentration of H+ in a solution, while bases accept H+ ions, which decreases the concentration of H+.

Atoms are the fundamental units or "building blocks" of all substances. They are the smallest particles that make up matter and cannot be broken down into smaller components without losing their chemical properties. Atoms combine together to form molecules and compounds, which then make up the various substances we encounter in our daily lives. Therefore, the correct answer is "building blocks."

Covalent bonds tend to be stronger than ionic bonds, but they are not always so.

Cohesion keeps water molecules together. It means that molecules resist seperating from one another. E.g: Water with its hydrogen bonds. The bond is so strong that the molecules stay together rather than spreading out like a thin film when you throw a pebble into a pond.

An example of a solvent is water.

In order for a solution to be neutral, the number of H+ ions (acidic) must be the same as the number of OH- ions (basic). This balance of acidic and basic ions results in a solution with a pH value of 7.

A buffer system is a solution that helps maintain a consistent pH level. It resists changes in pH when small amounts of acid or base are added to it. This is important because many biological processes and reactions require a specific pH level to function properly. By keeping the pH within a consistent range, a buffer system ensures that these processes can occur smoothly without any drastic changes in acidity or basicity.

If nonpolar, the atoms participating in the bond are sharing electrons equally. There is no difference in charge between the two ends of such bonds. Nonpolar covalent bonds form between atoms with identical electronegativity.

0-7 is acidic, 7-14 is basic. 7 is neutral.

Isotopes of the same element have the same number of protons. This is because isotopes are atoms of the same element that have different numbers of neutrons, but the same number of protons. The number of protons determines the element's identity, so isotopes of the same element will always have the same number of protons. The number of neutrons may vary, which results in different mass numbers for different isotopes.

An element is a pure substance. Each kind consists only of atoms with the same number of protons. Maria is wrong.

Water is an example. All water molecules have one oxygen and two hydrogen atoms. In a sea or lake, an ocean or a pool, its molecules have twice as many hydrogen as oxygen atoms.

Evaporation heat energy converts liquid water to gas. It takes heat to convert liquid water to gas, so the surface temperature of water decreases during evaporation. ( Can cool you off when you sweat)

Salts are dissolved easily in water and release ions other than H+ or OH-. For example= NaCl --- > Na+ + Cl-.

Polarity refers to the separation of charges in a molecule or bond. When there is a difference in electronegativity between atoms in a bond, the electrons are pulled towards the more electronegative atom, creating a slightly negative charge on that atom and a slightly positive charge on the other atom. This separation of charges creates distinct positive and negative regions in the molecule or bond, which is known as polarity.

A chemical bond is an attractive force that arises between two atoms when their electrons interact. This force pulls the atoms together and forms a bond between them. The electrons of one atom are attracted to the positively charged nucleus of the other atom, creating a stable arrangement. This attraction allows the atoms to share, transfer, or redistribute their electrons, leading to the formation of various types of chemical bonds such as covalent, ionic, or metallic bonds. Overall, the attractive force between the electrons of two atoms plays a crucial role in holding molecules and compounds together.

Compared to other liquids, water absorbs more heat before it becomes measurably hotter, since the water temperature is stable. This is due to the extensive hydrogen bonding that restricts the jiggling of water molecules.

A mixture is a combination of two or more substances that intermingle without forming chemical bonds. This means that the substances retain their individual properties and can be separated physically. Additionally, in a mixture, the proportions of the substances can vary, meaning that different amounts of each substance can be present in the mixture.

Electronegativity is a measure of an atom's ability to pull electrons from other atoms. Whether the pull is strong or weak depends on the atom's size and how many vacancies it has; it is not a measure of charge. Example: A chlorine atom uncharged, it has 17 protons and 17 electrons. On its valence electron's shell, it has 7 electrons. (which can hold eight) It has one vacancy. An uncharged chlorine atom is highly electronegative--- it can pull an electron away from another atom and fill its third shell.It would then become a chlorine ion. ( Cl-)

Basic solutions are substances that have a pH greater than 7. In the given list, the basic solutions are oven cleaner, ammonia, blood, Tums, egg white, toothpaste, bleach, and hair remover. These substances are known to have a pH greater than 7 and therefore can be classified as basic solutions.

Ionic bond, which is a strong mutual attraction of two oppositely charged ion, does not usually form by the direct transfer of an electron from one atom to another; rather, atoms that have already become ions stay close together because of their opposite charges. E.g: NaCl; in such solids, ionic bonds hold sodium and chloride ions in an orderly, cubic arrangement.