Which of the following is an example of an exothermic reaction?
Melting ice
Burning wood
Cooking an egg
Dissolving sugar in water
Correct Answer : B
Exothermic reactions are reactions that release energy in the form of heat, light, or sound. Burning wood is an example of an exothermic reaction because it releases heat and light. As the wood reacts with oxygen in the air, it undergoes a combustion reaction that releases energy in the form of heat and light. Melting ice is an endothermic reaction because it requires energy input to melt the solid ice into liquid water. Cooking an egg is a chemical reaction that involves denaturing the proteins in the egg, but it is not necessarily exothermic or endothermic. Dissolving sugar in water is also not an example of an exothermic reaction because it does not release energy in the form of heat, light, or sound.
TEAS 7 Exam Quiz Bank
HESI A2 Exam Quiz Bank
Find More Questions 📚
Teas 7 Questions: We got the latest updated TEAS 7 questions
100% Money Refund: 100% money back guarantee if you take our full
assessment pass with 80% and fail the actual exam.
Live Tutoring: Fully customized live tutoring lessons.
Guaranteed A Grade: All students who use our services pass with 90%
guarantee.
Related Questions
Correct Answer is B
Explanation
Carbohydrates are one of the main types of biomolecules and are composed of monomers called monosaccharides. Monosaccharides are simple sugars that cannot be further broken down into simpler sugars. They are usually composed of 3 to 7 carbon atoms and have a general formula of (CH2O)n, where n is a number between 3 and 7. Examples of monosaccharides include glucose, fructose, and galactose.
When two monosaccharides are joined together by a glycosidic bond, they form a disaccharide. Disaccharides are composed of two simple sugars and can be broken down into their constituent monosaccharides by hydrolysis. Examples of disaccharides include sucrose, lactose, and maltose.
Option a) is incorrect because it describes the composition of a disaccharide, not a monosaccharide. Option
c) is incorrect because both monosaccharides and disaccharides can be found in both plants and animals.
Option d) is incorrect because both monosaccharides and disaccharides can be used for energy storage and
structural purposes, depending on their specific structure and function in the organism.
![]() |
Correct Answer is B
Explanation
A buffer is a solution that resists changes in pH when small amounts of an acid or base are added. Buffers work by neutralizing added hydrogen ions (H⁺) or hydroxide ions (OH⁻), thereby maintaining a relatively stable pH. Buffers are made up of a weak acid and its conjugate base or a weak base and its conjugate acid.
- A. It decreases the pH of the solution: This is incorrect because a buffer does not always decrease pH; it resists changes in both directions.
- C. It causes the pH of a solution to become neutral: Incorrect because buffers do not necessarily make a solution neutral; they stabilize pH around a certain value.
- D. It permanently binds hydrogen ions: Incorrect as the binding is reversible, which is essential for maintaining pH balance.
Correct Answer is C
Explanation
The three major pairs of salivary glands are the parotid glands, sublingual glands, and submandibular glands.
- Parotid glands are located just in front of your ears.
- Sublingual glands are located below either side of your tongue, under the floor of your mouth.
- Submandibular glands are located below your jaw.
![]() |
Correct Answer is A
Explanation
The data collected by the researcher on the number of cars passing through a busy intersection at different times of the day for a month would be most useful to analyze traffic paterns during rush hour.
Correct Answer is C
Explanation
The molecular geometry of a molecule of sulphur dioxide (SO2) is bent or V-shaped. This is because of the presence of two lone pairs on the sulfur atom, which cause repulsion and distort the bond angles in the molecule.
SO2 has a central sulfur atom bonded to two oxygen atoms by double bonds. The two double bonds and the two lone pairs of electrons on sulfur result in a trigonal planar arrangement of electron pairs around the sulfur atom. However, the repulsion between the lone pairs causes the two oxygen atoms to be pulled closer together, resulting in a bent or V-shaped molecular geometry.
The bent molecular geometry of SO2 affects its properties, such as its polarity and reactivity. SO2 is a polar molecule due to the asymmetric distribution of electrons, which results in a partial positive charge on the sulfur atom and partial negative charges on the oxygen atoms. This polarity makes SO2 a good solvent and reactant in chemical reactions, as well as a contributor to air pollution and acid rain.
![]() |
Correct Answer is C
Explanation
Transfer RNA (tRNA) is a type of RNA molecule that carries amino acids to the ribosome during protein synthesis. Each tRNA molecule has a specific sequence of three nucleotides called an anticodon, which pairs with a complementary codon in the messenger RNA (mRNA) sequence. Each tRNA also carries a specific amino acid that corresponds to the codon it recognizes, allowing the ribosome to link the amino acids together in the correct order to form a protein.
In contrast, messenger RNA (mRNA) carries the genetic information from the DNA to the ribosome, where it serves as a template for protein synthesis. Ribosomal RNA (rRNA) is a component of the ribosome itself, where it helps to catalyze the formation of peptide bonds between amino acids. Small nuclear RNA (snRNA) is involved in splicing of pre-mRNA molecules during post-transcriptional processing.
![]() |
Correct Answer is C
Explanation
Vaccines are a type of preventative medicine that work by exposing the individual to a weakened or inactivated form of a pathogen (such as a virus or bacteria) or to a piece of the pathogen (such as a protein or sugar) that triggers an immune response in the body. This exposure allows the body to develop immunity to the pathogen without getting sick from the full-blown disease. Once the immune system has been primed, it can recognize and quickly respond to the pathogen if it is encountered again in the future, providing protection against the disease.
It is a common misconception that vaccines can cause the disease they are designed to protect against. This is not true. While some vaccines may cause mild symptoms such as a low-grade fever or soreness at the injection site, they do not cause the full-blown disease.
Vaccines provide active immunity, meaning that the body produces its own antibodies against the pathogen, rather than receiving pre-made antibodies as in passive immunity. Additionally, vaccines can be effective against both bacterial and viral infections, depending on the specific vaccine.
Correct Answer is A
Explanation
The vertebral column, also known as the spine or spinal column, is a series of bones called vertebrae that extend from the skull to the pelvis. It provides support for the body and protects the spinal cord. The five regions of the vertebral column, starting from the top and moving downwards, are:
- Cervical: This region is made up of seven vertebrae and is located in the neck. The first two cervical vertebrae, the atlas and the axis, are specialized to allow for head movement.
- Thoracic: This region is made up of twelve vertebrae and is located in the upper and middle back. The thoracic vertebrae are larger than the cervical vertebrae and articulate with the ribs.
- Lumbar: This region is made up of five vertebrae and is located in the lower back. The lumbar vertebrae are the largest and strongest of the vertebrae.
- Sacral: This region is made up of five fused vertebrae and is located in the pelvis. The sacrum forms the posterior wall of the pelvis and articulates with the hip bones.
- Coccygeal: This region is made up of four fused vertebrae and is located at the base of the vertebral column. The coccyx, or tailbone, provides atachment points for muscles and ligaments.
![]() |
Correct Answer is A
Explanation
Chlorophyll a is the primary pigment responsible for photosynthesis in plants. It is a green pigment that is essential for capturing light energy from the sun and converting it into chemical energy that can be used by the plant. Chlorophyll a absorbs light most efficiently in the blue and red parts of the spectrum, and reflects green light, giving plants their characteristic green color
Chlorophyll b is another type of chlorophyll that is also involved in photosynthesis, but it is not as abundant as chlorophyll a. Chlorophyll b absorbs light most efficiently in the blue and orange parts of the spectrum and reflects yellow-green light.
Carotenoids are pigments that are present in many plants and are involved in photosynthesis as well as protecting the plant from damage caused by excess light. Carotenoids are responsible for the orange, yellow, and red colors of many fruits and vegetables.
Anthocyanins are pigments that give plants their red, purple, and blue colors. While they are not directly involved in photosynthesis, they play a role in atracting pollinators and protecting the plant from damage caused by UV radiation.
Correct Answer is B
Explanation
Transcription is the process by which DNA is copied into RNA. During transcription, the DNA molecule unwinds and RNA polymerase reads the DNA sequence and synthesizes a complementary RNA molecule using the DNA as a template.
This question was extracted from the actual TEAS Exam. Ace your TEAS exam with the actual TEAS 7 questions, Start your journey with us today
Visit Naxlex, the Most Trusted TEAS TEST Platform With Guaranteed Pass of 90%.
Money back guarantee if you use our service and fail the actual exam. Option of personalised live tutor on your area of weakness.