Q: Name the one metal that melts below room temperature? Read this paragraph and choose the correct option from the provided answers: Metals have a wide range of melting points, but most are quite high. Only one metal (mercury) melts below room temperature. Others (such as gallium) are solid at room temperature but would melt at body temperature, so they can be melted simply by holding them in your hand. On the other end of the spectrum, tungsten has a melting point of 3422C. Figure below shows the melting points of various elements in their most common pure form. Choices: - aluminum - gold - bronze - mercury A:
mercury

Q: The combined gradient that affects an ion includes its concentration gradient and its what? Read this paragraph and choose the correct option from the provided answers: 5.3 Active Transport The combined gradient that affects an ion includes its concentration gradient and its electrical gradient. A positive ion, for example, might tend to diffuse into a new area, down its concentration gradient, but if it is diffusing into an area of net positive charge, its diffusion will be hampered by its electrical gradient. When dealing with ions in aqueous solutions, a combination of the electrochemical and concentration gradients, rather than just the concentration gradient alone, must be considered. Living cells need certain substances that exist inside the cell in concentrations greater than they exist in the extracellular space. Moving substances up their electrochemical gradients requires energy from the cell. Active transport uses energy stored in ATP to fuel this transport. Active transport of small molecular-sized materials uses integral proteins in the cell membrane to move the materials: These proteins are analogous to pumps. Some pumps, which carry out primary active transport, couple directly with ATP to drive their action. In co-transport (or secondary active transport), energy from primary transport can be used to move another substance into the cell and up its concentration gradient. Choices: - radiation gradient - cell membrane - electron bond - electrical gradient A:
electrical gradient

Q: Melting ice and grinding wood into sawdust are examples of what? Read this paragraph and choose the correct option from the provided answers: Melting ice and grinding wood into sawdust are examples of physical changes. Choices: - chemical changes - reversible changes - unpredictable changes - physical changes A:
physical changes

Q: What is destroying the layer of good ozone? Read this paragraph and choose the correct option from the provided answers: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. It's rate of loss has slowed with restrictions on pollutants, but it is still at risk. Choices: - greenhouse gas - water pollution - climate change - air pollution A:
air pollution