Physical Properties Vs Chemical Properties Quiz Chapter 2

This statement is true because organic compounds are defined as compounds that contain carbon atoms. Carbon is the key element in organic chemistry and is the basis for the structure and properties of organic compounds. Therefore, all organic compounds must contain carbon.

The molecule consisting of one carbon atom and two oxygen atoms is correctly written as CO2 because the chemical formula for carbon dioxide is CO2. In this formula, the carbon atom is represented by the symbol C and the oxygen atoms are represented by the symbol O. The subscript 2 indicates that there are two oxygen atoms present in the molecule.

The explanation for the given correct answer is that the atomic weight is indeed an average of the relative weights of an atom and its isotopes. Isotopes are atoms of the same element that have different numbers of neutrons, resulting in different atomic weights. Therefore, the atomic weight listed on the periodic table is an average value that takes into account the abundance of each isotope. As a result, the atomic weight may vary from the weight of a specific isotope.

The explanation for the given correct answer is that mixtures are composed of two or more substances that are physically combined, but they do not undergo any chemical reactions or bonding. On the other hand, compounds are formed when two or more elements chemically combine and form new substances with different properties. Therefore, the absence of chemical bonding between the components of a mixture is indeed the main difference between mixtures and compounds, making the statement true.

A charged particle is indeed generally called an ion. An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a positive or negative charge. This means that ions are charged particles, and they can be formed through various processes such as chemical reactions or the gain/loss of electrons in an electric field. Therefore, the statement "A charged particle is generally called an ion" is true.

Glucose is indeed an example of a monosaccharide. Monosaccharides are the simplest form of carbohydrates, consisting of a single sugar molecule. Glucose is a six-carbon sugar that is commonly found in fruits, honey, and the bloodstream of animals. It is an essential source of energy for living organisms and is used in cellular respiration to produce ATP. Therefore, the statement "Glucose is an example of a monosaccharide" is true.

Omega-3 fatty acids have been extensively studied and research suggests that they can indeed decrease the risk of heart disease. These essential fatty acids have been shown to reduce inflammation, lower blood pressure, decrease triglyceride levels, and improve overall heart health. They can also help prevent the formation of blood clots, which can lead to heart attacks. Therefore, the statement that Omega-3 fatty acids decrease the risk of heart disease is true based on current information and research.

Chemical bonding refers to the process of atoms or molecules combining to form new substances. In a mixture, the components are simply physically mixed together and can be separated without undergoing any chemical changes. Therefore, no chemical bonding occurs between the components of a mixture.

The statement is true because pH is a measure of the concentration of hydrogen ions in a solution. A lower pH indicates a higher concentration of hydrogen ions, while a higher pH indicates a lower concentration of hydrogen ions. Therefore, the lower the pH, the higher the hydrogen ion concentration.

Alpha particles are indeed a cause of lung cancer, second only to smoking. Despite being weak energy particles, they can cause significant damage to the cells in the lungs if inhaled. This damage can lead to the development of cancer over time. Therefore, the statement that alpha particles are second only to smoking as a cause of lung cancer is true.

Covalent bonds are generally more stable than ionic bonds. In a covalent bond, two atoms share electrons, creating a strong bond. This sharing of electrons allows both atoms to achieve a stable electron configuration. On the other hand, in an ionic bond, one atom donates electrons to another atom, creating a bond through the attraction of opposite charges. This type of bond is generally weaker and more easily broken. Therefore, the statement that covalent bonds are generally less stable than ionic bonds is false.

Hydrogen bonds are not comparatively strong bonds. In fact, they are weaker than covalent or ionic bonds. Hydrogen bonds occur when a hydrogen atom is attracted to an electronegative atom, such as oxygen or nitrogen. While they are important in many biological processes, such as the structure of DNA and protein folding, hydrogen bonds are relatively weak and can be easily broken.

A dipeptide is formed by the dehydration synthesis of two amino acids, not broken down. Dehydration synthesis is a chemical reaction that combines molecules by removing water, while hydrolysis is the process of breaking down molecules by adding water. Therefore, the statement that a dipeptide can be broken into two amino acids by dehydration synthesis is false.

Human blood has a pH of 7.35-7.45. The pH scale measures the acidity or alkalinity of a substance, with a pH below 7 being acidic, a pH of 7 being neutral, and a pH above 7 being alkaline. The pH range of 7.35-7.45 indicates that human blood is slightly alkaline or basic. This pH range is important for maintaining the proper functioning of various biological processes in the body, including enzyme activity and cell function. Deviations from this pH range can lead to health problems.

Emulsions and colloids are not the same thing. While both involve the dispersion of one substance within another, there is a distinction between the two. Emulsions refer specifically to the dispersion of immiscible liquids, such as oil and water, where one liquid is dispersed as droplets within the other. Colloids, on the other hand, can involve the dispersion of various substances, such as solid particles or liquid droplets, within a different medium. Therefore, the statement that emulsions and colloids are the same thing is incorrect.

This statement is false. Chemical properties are primarily determined by the arrangement and behavior of electrons in an atom, not by neutrons. Neutrons are subatomic particles that contribute to the mass of an atom but do not directly influence its chemical properties. The number of protons, which determines the element's identity, and the arrangement of electrons in the outermost energy level are the main factors that determine an atom's chemical properties.

Lipids are actually a rich source of stored energy. They contain more than twice the amount of energy per gram compared to carbohydrates or proteins. When the body needs energy, it can break down lipids and release this stored energy.

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. They have the same number of electrons because the number of electrons in an atom is determined by the number of protons. Therefore, the statement that isotopes differ from each other only in the number of electrons contained is false.

A solution with a pH of 2 indicates a high concentration of hydrogen ions, making it acidic. The lower the pH value, the higher the acidity of the solution. In this case, the pH of 2 suggests a strong acid.

The correct answer is DNA is a long, double-stranded molecule made up of A, T, G, and C bases. This statement accurately describes the structure and composition of DNA, which is a double helix made up of nucleotides containing the bases adenine (A), thymine (T), guanine (G), and cytosine (C). RNA, on the other hand, is a single-stranded molecule and tDNA is not a recognized form of nucleic acid.

The chemical formula CH4 represents one carbon atom bonded with four hydrogen atoms. This is known as methane, which is a simple organic molecule.

Riboflavin (vitamin B2) is an example of a coenzyme. Coenzymes are small organic molecules that are required for the proper functioning of enzymes. They assist enzymes in carrying out their specific reactions by transferring functional groups or electrons. Riboflavin, as a coenzyme, plays a crucial role in various metabolic processes, including the breakdown of carbohydrates, proteins, and fats for energy production. It is essential for the proper functioning of enzymes involved in these processes, making it a prime example of a coenzyme.

Amino acids joining together to make a peptide is an example of a synthesis reaction because it involves the combination of smaller molecules (amino acids) to form a larger molecule (peptide). In a synthesis reaction, two or more substances combine to form a more complex substance.

Carbohydrates are stored in the liver and muscles in the form of glycogen. Glycogen is a polysaccharide that serves as a storage form of glucose in the body. It is synthesized and stored when blood glucose levels are high, and it can be broken down into glucose when blood glucose levels drop, providing a quick source of energy for the body. Triglycerides are the storage form of fats, not carbohydrates. Glucose is a simple sugar and a component of glycogen, but it is not the storage form itself. Cholesterol is a type of lipid and is not involved in carbohydrate storage.

A long chain of simple sugars would be a polysaccharide because polysaccharides are complex carbohydrates composed of multiple monosaccharide units linked together. This is in contrast to monosaccharides, which are single sugar molecules, and proteins and nucleic acids, which are different types of macromolecules.

Salts are always ionic compounds because they are formed when a metal donates electrons to a non-metal, resulting in the formation of positive and negative ions. These ions are held together by strong electrostatic forces of attraction, creating a crystal lattice structure. This ionic bonding gives salts their characteristic properties such as high melting and boiling points, solubility in water, and ability to conduct electricity when dissolved or melted.

The four elements that make up about 96% of body matter are carbon, oxygen, hydrogen, and nitrogen. These elements are essential for the formation of molecules such as carbohydrates, lipids, proteins, and nucleic acids, which are the building blocks of life. Carbon provides the backbone for organic compounds, oxygen is necessary for respiration, hydrogen is involved in bonding and energy transfer, and nitrogen is a crucial component of proteins and nucleic acids. Together, these elements play a vital role in maintaining the structure and function of living organisms.

An atom with two protons would be very stable because it would have a full valence shell. The valence shell is the outermost shell of an atom, and it is most stable when it is completely filled with electrons. In this case, the atom would have two electrons in its valence shell, which is the maximum number of electrons that can occupy that shell. Therefore, the atom would not need to gain or lose any electrons to achieve stability, making it very stable.

The formula C6H12O6 represents a molecule that contains 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.

The statement that about 60 to 80% of the volume of most living cells consists of organic compounds is false. While organic compounds are important for cellular function, they do not make up such a large percentage of the cell's volume. The majority of a cell's volume is actually occupied by water, which makes up about 70-90% of the cell's total volume. Organic compounds, such as proteins, lipids, and nucleic acids, are present in smaller quantities within the cell.

A chain of 25 amino acids is called a polypeptide. A polypeptide is a long chain of amino acids that are linked together by peptide bonds. It is a precursor to a protein and can fold into a specific three-dimensional structure to perform its biological function.

HCO3- refers to bicarbonate ion, which is a negatively charged molecule made up of one carbon atom and three oxygen atoms. It is commonly found in the body, particularly in the blood and acts as a buffer to maintain the pH balance. Bicarbonate ion can act as a weak acid, donating a proton (H+) in certain chemical reactions. Therefore, the correct answer is "a bicarbonate ion".

The valence shell of an atom is the outermost shell that contains electrons. In this case, since atom X has seventeen protons, it belongs to the element chlorine (Cl), which has an atomic number of 17. Chlorine has a total of three electron shells, with the valence shell being the third shell. The valence shell can hold a maximum of eight electrons, but in this case, there are seven electrons in the valence shell of atom X.

Hydrogen bonds often bind different parts of a molecule into a specific 3-dimensional shape. Hydrogen bonding occurs when a hydrogen atom is attracted to a highly electronegative atom, such as oxygen or nitrogen. In the context of molecules, hydrogen bonds can form between different parts of the same molecule or between different molecules. These bonds play a crucial role in determining the shape and stability of molecules, as they can cause certain regions of the molecule to fold or twist, leading to the formation of complex 3-dimensional structures.

Sucrose is a disaccharide because it is composed of two monosaccharides, glucose and fructose, joined together by a glycosidic bond. Disaccharides are carbohydrates that are made up of two sugar molecules.

A chemical reaction in which bonds are broken is usually associated with the release of energy. When bonds are broken, the potential energy stored in those bonds is converted into kinetic energy, resulting in the release of energy. This energy can be in the form of heat, light, or sound, depending on the specific reaction. The release of energy is a characteristic of exothermic reactions, where the overall energy of the system decreases.

The coiling of the protein chain backbone into an alpha helix is referred to as the secondary structure. The secondary structure of a protein refers to the local folding patterns that occur within a specific region of the protein chain. In the case of an alpha helix, the backbone of the protein chain forms a tightly coiled structure resembling a spiral staircase. This secondary structure is stabilized by hydrogen bonds between the amino acid residues in the backbone. The secondary structure is one of the key elements that contribute to the overall three-dimensional structure and function of a protein.

ATP (adenosine triphosphate) is a molecule that provides energy for cellular processes. It is commonly used in chemical work, such as synthesis of molecules, and mechanical work, such as muscle contraction. ATP is also involved in transport processes, such as the movement of ions and molecules across cell membranes. However, it is not directly involved in the production or function of pigments, which are responsible for the coloration of organisms.

The chemical symbol OO represents a double bond between two oxygen atoms. In a double bond, two pairs of electrons are shared between the atoms, resulting in a stronger bond compared to a single bond. This notation indicates that the oxygen atoms are connected by a double bond, allowing them to share four electrons.

Iron is a heavy metal that is normally found in the body. It is an essential mineral that plays a crucial role in various bodily functions, including the production of red blood cells and the transportation of oxygen. Iron deficiency can lead to anemia, fatigue, and impaired cognitive function. While lead, mercury, and arsenic are also heavy metals, they are not normally found in the body and can be toxic when present in high levels.

Neutral fats have a ratio of 3:1 of fatty acids to glycerol. This means that for every three fatty acids, there is one glycerol molecule present in neutral fats. This ratio is important because it determines the structure and properties of neutral fats, including their solubility and ability to store energy efficiently.

A dipole is a term used to describe a molecule that has a separation of positive and negative charges. This occurs when there is an uneven distribution of electrons within the molecule, causing one end to be slightly positive and the other end to be slightly negative. This polarity allows the molecule to interact with other polar molecules through attractive forces, such as hydrogen bonding. Therefore, a dipole is correctly described as a polar molecule.

Eledin is not a fibrous protein found in the body. Keratin, elastin, and collagen are all examples of fibrous proteins that are present in various tissues and structures in the body.

A phospholipid is usually partially polar and partially nonpolar because it consists of a hydrophilic (polar) head and a hydrophobic (nonpolar) tail. The head is composed of a phosphate group and glycerol, which are polar molecules, while the tail is made up of fatty acid chains, which are nonpolar. This unique structure allows phospholipids to form the lipid bilayer of cell membranes, with the polar heads facing the aqueous environment and the nonpolar tails facing each other.

The genetic information is coded in DNA by the sequence of the nucleotides. This means that the specific order of the four nucleotide bases (adenine, thymine, cytosine, and guanine) in a DNA molecule determines the genetic instructions for building and functioning of an organism. The sequence of nucleotides forms the genetic code that carries the instructions for protein synthesis and other cellular processes. The regular alteration of sugar and phosphate molecules, the three-dimensional structure of the double helix, and the arrangement of the histones are important aspects of DNA structure and packaging, but they do not directly determine the genetic information.

Fibrous proteins are known for their stability and insolubility in water. This is because they have a highly ordered and repetitive structure, which allows them to form strong and stable interactions with each other. These proteins are often found in structural components of cells and tissues, such as collagen in connective tissues and keratin in hair and nails. Their stability and insolubility in water make them suitable for providing strength and support to these structures.

The phosphate in a DNA molecule serves to hold the molecular backbone together. The phosphate groups form strong covalent bonds with the sugar molecules, creating a stable backbone for the DNA strand. This backbone provides structural support and stability to the DNA molecule, allowing it to maintain its double helix structure. Without the phosphate groups, the DNA molecule would not be able to maintain its shape and integrity.

Sodium (Na) is necessary for proper conduction of nervous impulses. Nervous impulses are electrical signals that travel along nerve cells, and sodium ions play a crucial role in this process. When a nerve impulse is generated, sodium channels open in the cell membrane, allowing sodium ions to enter the cell. This influx of sodium ions creates a positive charge inside the cell, which triggers the propagation of the nerve impulse along the nerve fiber. Without sodium, the conduction of nerve impulses would be impaired, leading to communication breakdown within the nervous system.

Enzymes are actually known to lower the activation energy needed to start a reaction, not raise it. This is one of the main functions of enzymes - to speed up chemical reactions by reducing the energy barrier required for the reaction to occur.

Molarity is a unit of concentration that represents the number of moles of solute per liter of solution. In this case, it is stated that molarity is one mole of solute per 1000 ml of solution. This means that for every 1000 ml of solution, there is one mole of solute present.