PAX Science exam questions fully solved & updated 2024

A person blows his breath into a straw that is placed in limewater. The limewater becomes cloudy because the person's breath contains carbon dioxide A student focuses sunlight to a point with a thin converging (convex) lens. Which of these direct measurements can the student make as a result of this experiment? The approximate focal length of the lens. Brainpower Read More Previous Play Next Rewind 10 seconds Move forward 10 seconds Unmute 0:00 / 0:00 Full screen A woman suddenly chokes on a piece of food and clutches frantically at her throat. An immediate remedy is to apply quick, hard pressures successively to her abdomen, just beneath her diaphragm. An unknown gas is more dense than air, does not support combustion, and turns a limewater solution cloudy. This gas is most probably carbon dioxide Guard cells which can be found in the leaves of plants are most closely associated with which of these processes? Evaporation of water from the plant. If a red light is passed through a dilute solution of chlorophyll solution, the spectrophotometer will detect what amount of transmittance of this light? 50 - 75% If the medulla of the brain in a human was damaged, which of these conditions would most likely result? Difficulty in breathing Night blindness in humans is caused by a lack of Vitamin A In varieties of matter, the term heterogeneous may be applied to mixtures, but not elements or compounds. Heat energy is absorbed in which of these phase changes? Br2 (l) - Br2(g) Periodontitis is an inflammatory condition of the gum tissue that surrounds the neck of each tooth. The atoms of an element with seven valence electrons are most probably classified as nonmetals. The bending of a wave around an obstacle is known as diffraction The inherited factors that are transmitted in an organism from generation to generation are called its genotype Which of these conditions is associated with smoking? emphysema Which of these equations best illustrates a synthesis reaction? 2Na + Cl2 - 2NaCl Which of these pairs of units measures the same quantity? Newton and joule / Newton and watt ? Which of these quantities is a vector quantity? Force Which of these single instruments may be used to measure the current flowing through a circuit? Ammeter Which of these substances contains a nonpolar covalent bond? O2 Which part of the cell structure controls the passage of materials into and out of the cell? Plasma membrane. Which part of the human central nervous system controls voluntary movements? Cerebrum. While working in the chemistry laboratory, a student spills dilute hydrochloric acid on her hand. What is the first action this student should take? Flush her hand with large quantities of water. Within which of these structures of the female reproductive tract is the human egg fertilized? Fallopian tube. A tincture is a solution in which alcohol is the solvent. A circuit contains three 3-ohm (W) resistors in series. What is the equivalent resistance of this combination? 9W A quantity that has both magnitude and direction is called a(n) vector. A recently discovered species has these characteristics: amniotic eggs, a four-chambered heart, and lightweight, honeycombed bones. Which of these ADDITIONAL characteristics is likely to be present? Feathers for flying. A substance that increases the speed of a reaction by lowering its activation energy is called a catalyst An example of an adaptation to prevent water loss in plants is waxy epidermis At room temperature, which of these substances exists as diatomic molecules? oxygen Compounds with the same type and number of atoms and the same chemical bonds but different spatial arrangements of these bonds and atoms are called structural isomers. The calorie and the kilocalorie are units of energy The force of gravity on an object is that object's weight The light sensitive cells of the eye are called rods and cones. Which of these layers of the eye are they found in? retina The meiotic division of cells leads to the production of cells that contain half the usual number of chromosomes. The most probable area of study that would show the prevalence of mental illness in mid-Manhattan is that of epidemiology The normal boiling temperature for water is 100° when measured on which of these scales? celsius The vertical columns on the periodic chart are known as groups What is the pH of a solution whose H+ ion concentration is 1 x 10-2 mole per liter? 2