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Questions in chemistry

[Done] During the action of a sodium-potassium pump, 50 ATP molecules are spent. Predict how many sodium ions are transported across the cell membrane. A. 50 B. 100 C. 150 D. 200

[Done] Stella has poured 3 cups of water into a 1-L soda bottle. She then sealed the bottle and placed it in the sunlight. What natural process can Stella study with the model she built? A. Nitrogen cycle B. Rock cycle C. Carbon cycle D. Water cycle

[Done] Which electron transition involves the most energy?

[Done] A solution that has a relatively large quantity of solute dissolved in the solvent is: A. heterogeneous B. dilute C. dissociated D. concentrated Please explain the answer.

[Done] According to early chemists, which substances were classified as elements? A. Those that could not be broken down further by physical means. B. Those that could not be broken down further by chemical means. C. Those that had higher numbers of protons in their atoms. D. Those that had an atomic mass that could be measured.

[Done] In Chemistry, in the following type of shorthand, what does the number next to the element name mean? Hydrogen-3

[Done] An ionic bond can be formed when one or more electrons are: A) Equally shared between two atoms B) Unequally shared by two atoms C) Transferred from the nucleus of one atom to the nucleus of another atom D) Transferred from the valence shell of one atom to the valence shell of another atom

[Done] Muscle tissue is made up of cells that contract and release to produce movement. Which process provides the energy that the cells need to contract? A. respiration B. meiosis C. photosynthesis D. mitosis

[Done] What is the first step in creating a unit conversion factor?

[Done] Copper has a density of 8.920 g/cm\(^3\). 1. What mass of copper will occupy 45 cm\(^3\)? 2. What volume of copper will have a mass of 1.0 kg?