A scientist would most likely need to update her model when it no longer supports the latest results.
Increase, because you need heat to melt a solid to a liquid, so the temperature will have to get greater.
Answer:
True
Explanation:
There are 9 essential amino acids which cannot be made by the body and have to be obtained from food.
They are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine
Answer:
The cooler water is denser
Explanation:
Convection drives the boiling of water placed on a stove in a kettle.
During convection, heat is circulated by density differences in portions of a fluid.
Convection is a form of heat transfer in fluids especially gas and liquid.
- In boiling water, the heat is supplied to the base of the stove.
- The water at the bottom on heat becomes lighter as the molecules gain more kinetic energy.
- The colder part of the water on top sinks to replace the less dense on below.
- This exchange sets up convection cells in the kettle.
Reaction of sodium with water
Sodium metal reacts rapidly with water to form a colourless solution of sodium hydroxide (NaOH) and hydrogen gas (H2). The resulting solution is basic because of the dissolved hydroxide. The reaction is exothermic. During the reaction, the sodium metal may well become so hot that it catches fire and burns with a characteristic orange colour. The reaction is slower than that of potassium (immediately below sodium in the periodic table), but faster than that of lithium (immediately above sodium in the periodic table).
2Na(s) + 2H2O → 2NaOH(aq) + H2(g)
