1.
The atom is made of 3 subatomic particles. The subatomic particle found in the nucleus with no charge is the ___________.
Correct Answer
B. Neutron
Explanation
The correct answer is neutron. Neutrons are subatomic particles found in the nucleus of an atom and they have no charge. Electrons have a negative charge and are found outside the nucleus, while protons have a positive charge and are also found in the nucleus. Therefore, the neutron is the only subatomic particle mentioned in the options that fits the description of being found in the nucleus with no charge.
2.
The __________ is the smallest unit of matter.
Correct Answer
B. Atom
Explanation
An atom is the smallest unit of matter that retains the chemical properties of an element. It consists of a nucleus, which contains positively charged protons and uncharged neutrons, surrounded by negatively charged electrons. Atoms combine to form molecules, which are made up of two or more atoms bonded together. A polar molecule is a type of molecule that has a slightly positive end and a slightly negative end due to an uneven distribution of electrons. An ionic compound is a compound composed of positive and negative ions held together by electrostatic forces.
3.
An _______ bond is a bond in which electrons are transferred between a metal and a nonmetal.
Correct Answer
B. Ionic
Explanation
In an ionic bond, electrons are transferred between a metal and a nonmetal. This type of bond occurs when there is a large difference in electronegativity between the two atoms, causing one atom to donate electrons to the other. This results in the formation of positively charged metal ions and negatively charged nonmetal ions, which are held together by electrostatic attraction.
4.
An acid has a pH below ______.
Correct Answer
A. 7
Explanation
An acid has a pH below 7 because pH is a measure of the concentration of hydrogen ions in a solution. Acids release hydrogen ions when dissolved in water, which increases the concentration of hydrogen ions and lowers the pH. A pH below 7 indicates an acidic solution, while a pH above 7 indicates a basic or alkaline solution. Therefore, the correct answer is 7.
5.
Water is made of 1 oxygen molecule and _____ hydrogen atoms.
Correct Answer
B. 2
Explanation
Water is made of 1 oxygen molecule and 2 hydrogen atoms. This is because the chemical formula for water is H2O, which means there are two hydrogen atoms bonded to one oxygen atom.
6.
The water molecule is _________ because there is an uneven distribution of electrons within the molecule.
Correct Answer
C. Polar
Explanation
The water molecule is polar because there is an uneven distribution of electrons within the molecule. This is due to the oxygen atom being more electronegative than the hydrogen atoms, causing the oxygen atom to attract the shared electrons more strongly. As a result, the oxygen atom has a partial negative charge, while the hydrogen atoms have partial positive charges. This uneven distribution of charges creates a polar molecule, with a slight positive end and a slight negative end.
7.
A group of atoms bound together
Correct Answer
B. Molecule
Explanation
A molecule is a group of atoms bound together by chemical bonds. It is the smallest unit of a compound that retains the chemical properties of that compound. In this context, the other options are not the best fit. A proton is a subatomic particle found in the nucleus of an atom, not a group of atoms bound together. An atom is the basic unit of matter, but it does not necessarily consist of a group of atoms. A compound is a substance composed of two or more different elements, but it does not necessarily refer to a group of atoms bound together. Therefore, the best answer is molecule.
8.
All of these are major organic compounds except
Correct Answer
D. Acids
Explanation
Acids are not considered major organic compounds because they are not classified as macromolecules like carbohydrates, lipids, and proteins. Acids are a class of compounds that release hydrogen ions when dissolved in water, and they do not play a significant role in the structure and function of living organisms. In contrast, carbohydrates, lipids, and proteins are essential for various biological processes and are considered major organic compounds.
9.
All the substances listed are Inorganic except
Correct Answer
D. Proteins
Explanation
Acids, bases, and salts are all inorganic substances. Acids are compounds that release hydrogen ions when dissolved in water, bases release hydroxide ions, and salts are compounds formed from the reaction between an acid and a base. Proteins, on the other hand, are organic compounds made up of amino acids and are essential for the structure and function of living organisms. Therefore, proteins are the only substance listed that is organic, while the rest are inorganic.
10.
Fats and oils are examples of
Correct Answer
B. Lipids
Explanation
Fats and oils are examples of lipids. Lipids are a class of organic compounds that are insoluble in water but soluble in organic solvents. They are characterized by their high energy content and are an important source of energy for the body. Fats and oils, which are commonly found in foods such as butter, olive oil, and avocado, are types of lipids that provide essential fatty acids and play a role in various biological processes.
11.
Large Molecules made up of amino acids held together in long folded chains by peptide bonds.
Correct Answer
A. Proteins
Explanation
Proteins are large molecules composed of amino acids that are connected by peptide bonds. These amino acids form long, folded chains, giving proteins their unique structure and function. Unlike other options such as starches, carbohydrates, and cholesterol, proteins are specifically characterized by their amino acid composition and peptide bond formation. Therefore, the correct answer is proteins.
12.
Neutrons are
Correct Answer
B. Noncharged particles in nucleus.
Explanation
Neutrons are noncharged particles in the nucleus. Unlike protons, which have a positive charge, neutrons have no charge at all. They are essential components of an atom and help to stabilize the nucleus by counteracting the repulsive forces between positively charged protons. Neutrons also play a crucial role in determining an atom's mass, as they contribute to its atomic weight without affecting its overall charge.
13.
Number of protons and neutrons in the nucleus
Correct Answer
D. Atomic mass
Explanation
The atomic mass of an element is determined by the number of protons and neutrons in its nucleus. Protons have a positive charge and neutrons have no charge, so they contribute to the mass of the atom. The atomic mass is measured in atomic mass units (amu) and is an average of the masses of all the isotopes of an element. It is an important characteristic of an element as it helps in identifying and classifying elements in the periodic table.
14.
Substances whose molecules have more than one kind of atom
Correct Answer
B. Compound
Explanation
A compound is a substance whose molecules are made up of more than one kind of atom. In a compound, atoms of different elements are chemically bonded together to form a new substance with unique properties. Isotopes are atoms of the same element with different numbers of neutrons, while chemical elements refer to the pure substances made up of only one type of atom. Cations are positively charged ions formed when an atom loses electrons. Therefore, the correct answer is compound.
15.
Water is a
Correct Answer
B. Solvent
Explanation
Water is considered a solvent because it has the ability to dissolve a wide variety of substances. Its polarity allows it to form hydrogen bonds with other molecules, which helps in breaking down and dispersing solute particles. Water's solvent properties are essential for many biological and chemical processes, as it enables the transportation of nutrients and waste products within living organisms. Additionally, water's solvent nature plays a crucial role in weathering and erosion processes, as it can dissolve minerals and other substances from rocks and soil.
16.
Which as a positively charged particle in the nucleus
Correct Answer
B. Proton
Explanation
The correct answer is Proton. Protons are positively charged particles that are found in the nucleus of an atom. They have a mass of approximately 1 atomic mass unit and are responsible for determining the atomic number of an element. Electrons, on the other hand, are negatively charged particles that orbit the nucleus, while neutrons are neutral particles also found in the nucleus. Matter is a general term that refers to anything that has mass and occupies space.
17.
An atom has 12 electrons, 11 protons, and 11 neutrons. What is its atomic number?
Correct Answer
A. 11
Explanation
The atomic number of an atom is equal to the number of protons it has. In this case, the atom has 11 protons, so its atomic number is 11.
18.
The number of protons in an atom of an element
Correct Answer
D. Atomic number
Explanation
The atomic number of an element represents the number of protons in the nucleus of an atom of that element. It is a unique identifier for each element and determines its position on the periodic table. Atomic weight refers to the average mass of all the isotopes of an element, while atomic mass is the mass of a specific isotope. Atom is a general term for the smallest unit of matter, and it consists of protons, neutrons, and electrons. Therefore, the correct answer is atomic number.
19.
A solution with excess hydrogen ion (H+) concentration:
Correct Answer
C. Acid
Explanation
A solution with excess hydrogen ion (H+) concentration is considered an acid. Acids are substances that release hydrogen ions when dissolved in water. The excess of hydrogen ions in the solution indicates that it has a higher concentration of H+ ions, making it acidic. Acids are known to have a pH value less than 7 and can react with bases to form salts and water.
20.
These molecules primarily serve to provide the body with energy:
Correct Answer
A. Carbohydrates
Explanation
Carbohydrates primarily serve to provide the body with energy because they are broken down into glucose, which is the body's main source of fuel. When carbohydrates are consumed, they are converted into glucose and stored in the liver and muscles as glycogen. This glycogen can be quickly broken down into glucose when the body needs energy. Additionally, carbohydrates are the preferred source of energy for the brain and central nervous system.
21.
These molecules serve as an energy store and makeup the majority of a cell membrane:
Correct Answer
C. Lipids
Explanation
Lipids serve as an energy store and make up the majority of a cell membrane. They are a diverse group of molecules that include fats, oils, and waxes. Lipids are hydrophobic, meaning they do not mix well with water. This property allows them to form the lipid bilayer, which is the main component of cell membranes. Additionally, lipids can be broken down to release energy when needed by the cell. Therefore, lipids are essential for energy storage and the structural integrity of cell membranes.
22.
These molecules make up enzymes:
Correct Answer
B. Proteins
Explanation
Proteins are made up of amino acids and are essential for the structure and function of enzymes. Enzymes are biological catalysts that speed up chemical reactions in the body. They play a crucial role in various physiological processes such as digestion, metabolism, and DNA replication. Carbohydrates, lipids, acids, and bases are not directly involved in the composition of enzymes.
23.
These molecules are made of numerous amino acids:
Correct Answer
B. Proteins
Explanation
Proteins are indeed made up of numerous amino acids. Amino acids are the building blocks of proteins, and they are linked together through peptide bonds to form long chains. These chains then fold into complex three-dimensional structures, giving proteins their unique functions. Carbohydrates, lipids, acids, and bases are not made up of amino acids and do not have the same structural complexity or diversity as proteins.
24.
These molecules include starch and cellulose:
Correct Answer
A. Carbohydrates
Explanation
Carbohydrates are a group of organic compounds that include molecules such as starch and cellulose. Starch is a polysaccharide that serves as a storage form of energy in plants, while cellulose is a structural polysaccharide found in the cell walls of plants. Both starch and cellulose are composed of glucose monomers linked together in different ways. Therefore, carbohydrates are the correct answer as they encompass these specific molecules.
25.
This is a molecule found in the cell wall of plants.
Correct Answer
C. Cellulose
Explanation
Cellulose is a molecule found in the cell wall of plants. It is a complex carbohydrate made up of glucose units linked together. Cellulose provides structural support to the plant cell wall and gives rigidity to plant tissues. Unlike starch, which is a storage form of glucose in plants, cellulose cannot be easily broken down by most organisms due to its strong bonds. Lipids and enzymes are not typically found in the cell wall of plants, making cellulose the correct answer.
26.
This a molecule is a catalyst:
Correct Answer
E. Enzymes
Explanation
Enzymes are proteins that act as catalysts in biological reactions. They speed up the rate of chemical reactions by lowering the activation energy required for the reaction to occur. Unlike other molecules listed, such as glucose, starch, cellulose, and lipids, enzymes are not themselves consumed or changed during the reaction. Instead, they facilitate the reaction between other molecules. Therefore, enzymes can be considered as catalysts in biological systems.
27.
This molecule is an immediate source of energy for all living cells:
Correct Answer
A. Glucose
Explanation
Glucose is the correct answer because it is a simple sugar that can be easily broken down by cells to release energy through cellular respiration. It is the primary source of energy for all living cells and is used in various metabolic processes to produce ATP, the main energy currency of cells. Starch and cellulose are complex carbohydrates that need to be broken down into glucose before they can be used as an energy source. Lipids, such as fats and oils, can also be used for energy, but glucose is the immediate and preferred source. Enzymes are biological catalysts that facilitate biochemical reactions and do not directly provide energy.
28.
This molecule is made of many, many sugars bound together:
Correct Answer
B. Starch
Explanation
Starch is a polysaccharide made up of many glucose molecules bound together. It is a complex carbohydrate that serves as a storage form of energy in plants. Starch molecules are composed of two types of glucose polymers, amylose and amylopectin, which are arranged in a branched structure. Starch is commonly found in foods such as potatoes, rice, and wheat, and it can be broken down by enzymes in the body to release glucose for energy.
29.
2 H2 + O2 -> 2 H2OIn the above reaction, how many atoms of reactants are depicted?
Correct Answer
C. 6
Explanation
In the given reaction, there are 2 molecules of H2 and 1 molecule of O2 as reactants. Each H2 molecule contains 2 atoms of hydrogen, so 2 H2 molecules contain a total of 4 hydrogen atoms. The O2 molecule contains 2 atoms of oxygen. Therefore, the total number of atoms in the reactants is 4 hydrogen atoms + 2 oxygen atoms = 6 atoms.
30.
2 H2 + O2 -> 2 H2OIn the above reaction, how many molecules of reactants are depicted?
Correct Answer
B. 3
Explanation
In the given reaction, there are 2 molecules of H2 and 1 molecule of O2 depicted as reactants. Therefore, the total number of molecules of reactants depicted is 3.
31.
2 H2 + O2 -> 2 H2OIn the above reaction, what is/are the products?
Correct Answer
C. Water
Explanation
The given reaction represents the combination of hydrogen gas (H2) and oxygen gas (O2) to form water (H2O). Therefore, the product of this reaction is water.
32.
How many molecules of reactants?
Correct Answer
C. 3
Explanation
The answer is 3 because the question is asking for the number of molecules of reactants. Since there is no additional information provided, we can assume that there are 3 molecules of reactants involved in the reaction.
33.
How many grams of starch in this product?
Correct Answer
C. 5
Explanation
This product contains 5 grams of starch.
34.
Which of the following is a polymer?
Correct Answer
D. Protein
Explanation
Protein is the correct answer because it is a polymer. A polymer is a large molecule made up of repeating subunits called monomers. Proteins are composed of amino acids, which act as the monomers. Glucose, amino acid, and sugar are all small molecules and not polymers. Element is not a compound and therefore cannot be a polymer.
35.
An atom has 12 electrons, 11 protons, and 11 neutrons. What is its atomic mass?
Correct Answer
C. 22
Explanation
The atomic mass of an atom is determined by the sum of its protons and neutrons. In this case, the atom has 11 protons and 11 neutrons, so the atomic mass is 11 + 11 = 22.
36.
How many atoms of the product?
Correct Answer
E. 9
Explanation
The question is asking for the number of atoms of the product. Since the answer is 9, it means that there are 9 atoms of the product.
37.
Which carbohydrate is found in the cell wall of plants?
Correct Answer
D. Cellulose
Explanation
Cellulose is the correct answer because it is a carbohydrate that is found in the cell wall of plants. It provides structural support and rigidity to plant cells. Glucose and starch are also carbohydrates, but they are not specifically found in the cell wall. Enzyme is a type of protein and not a carbohydrate.
38.
How many grams of cellulose are in this product?
Correct Answer
A. 0
Explanation
The correct answer is 0 because cellulose is not present in the product.
39.
Which of the following is NOT an organic molecule?
Correct Answer
C. CO2
Explanation
CO2 is not an organic molecule because it does not contain carbon-hydrogen bonds. Organic molecules are characterized by the presence of carbon atoms bonded to hydrogen atoms, along with other elements such as oxygen, nitrogen, and sulfur. In contrast, CO2 consists of one carbon atom bonded to two oxygen atoms, with no hydrogen atoms present. Therefore, CO2 is classified as an inorganic molecule.
40.
Which of the following is an ionic compound?
Correct Answer
C. LiO
Explanation
LiO is an ionic compound because it consists of a metal (Li) and a non-metal (O). In ionic compounds, electrons are transferred from the metal to the non-metal, resulting in the formation of ions with opposite charges. LiO is formed by the transfer of one electron from Li to O, creating Li+ and O- ions. This electrostatic attraction between the oppositely charged ions holds the compound together, making it an ionic compound.