What does a concave lens look like? A concave lens is a lens that possesses at least one surface that curves inwards. It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used […]
Why is alkaline hydrolysis preferred?
Why is alkaline hydrolysis preferred? Hydrolysis using dilute alkali There are two big advantages of doing this rather than using a dilute acid. The reactions are one-way rather than reversible, and the products are easier to separate. Why is hydrolysis reversible? Hydrolysis is a reversible reaction, meaning that the alcohol and acid groups can react […]
What is sodium-22 used for?
What is sodium-22 used for? use of sodium Of the radioactive artificial isotopes, sodium-22 (2.6-year half-life, the longest half-life of a sodium isotope) is used as a radioactive tracer for natural sodium. Sodium-24 (15-hour half-life) is limited in use by its short life and is produced by irradiation in a nuclear reactor. Is sodium-22 stable? […]
How do you increase the mechanical advantage of a screw?
How do you increase the mechanical advantage of a screw? Screws move objects to a greater depth (or higher elevation) by increasing the force applied to the screw. The mechanical advantage of a screw is always greater than 1 because the output force applied by the screw is greater than the input force applied to […]
When was the last magnetic reversal?
When was the last magnetic reversal? The reversal was dated to approximately 15 million years ago. In August 2018, researchers reported a reversal lasting only 200 years. But a 2019 paper estimated that the most recent reversal, 780,000 years ago, lasted 22,000 years. How long does it take for Earth magnetic field to reverse? about […]
Can a room be cooled indefinitely by leaving the door of the refrigerator open?
Can a room be cooled indefinitely by leaving the door of the refrigerator open? No, the room can’t be cooled by leaving the door of an electric refrigerator open. In fact the temperature of the room rises because the refrigerator extracts heat from the freezing chambers and rejects it to the surrounding air in the […]
What are the 3 kinds of solubility?
What are the 3 kinds of solubility? Based on the concentration of solute dissolves in a solvent, solutes are categorized into highly soluble, sparingly soluble or insoluble. Does base increase solubility? The anion in sparingly soluble salts is often the conjugate base of a weak acid that may become protonated in solution, so the solubility […]
How breccia is formed?
How breccia is formed? Breccia forms where broken, angular fragments of rock or mineral debris accumulate. One of the most common locations for breccia formation is at the base of an outcrop where mechanical weathering debris accumulates. Another is in stream deposits a short distance from the outcrop or on an alluvial fan. How hard […]
When a metal jar lid is difficult to remove from a glass jar you can run hot water on the lid and then it is easier to open Why?
Is sweating positive or negative feedback?
Is sweating positive or negative feedback? Another example of negative feedback occurs when your body’s temperature begins to rise and a negative feedback response works to counteract and stop the rise in temperature. Sweating is a good example of negative feedback. Is body temperature positive or negative feedback? (b) Body temperature is regulated by negative […]