You are given a new situation: Justin and Alejandro are conducting a chemical experiment involving sodium hydroxide. A key part of the reaction is ensuring that the sodium hydroxide is dissolved in water before adding the other materials. Justin adds the sodium hydroxide to reaction A, and begins stirring the mixture with a spoon. Alejandro also adds sodium hydroxide to his reaction, reaction B, but doesn't stir it because he is lazy. and a hint : When you add sugar to a cold drink, you may stir it to help the sugar dissolve. If you don't stir, the sugar may eventually dissolve, but it will take much longer. Stirring is one of several factors that affect how fast a solute dissolves in a solvent. Temperature is another factor. A solid solute dissolves faster at a higher temperature. For example, sugar dissolves faster in hot tea than in ice tea. A third factor that affects the rate of dissolving is the surface area of the solute. For example, if you put granulated sugar in a glass of ice tea, it will dissolve more quickly than the same amount of sugar in a cube. That's because granulated sugar has much more surface area than a cube of sugar. You can see videos of all three factors at these URLs Please answer this question : Whose sodium hydroxide, Justin's or Alejandro's, will dissolve faster?
Ans: Justin's

You are given a new situation: Italy and Greece attended the World Ecological Conference. they were looking for solutions to improve their environment. Italy's air was very polluted, while Greece had problems with drought. and a hint : One result of air pollution is acid rain. Acid rain is precipitation with a low (acidic) pH. This rain can be very destructive to wildlife. When acid rain falls in forests, freshwater habitats, or soils, it can kill insects and aquatic life. It causes this damage because of its very low pH. Sulfur oxides and nitrogen oxides in the air both cause acid rain to form ( Figure below ). Sulfur oxides are chemicals that are released from coal-fired power plants. Nitrogen oxides are released from motor vehicle exhaust. Please answer this question : Which country had precipitation with a higher pH?
Ans: Greece

You are given a new situation: Gary and Joe are two farmers. Joe's farm has a depleted soil, while Gary started agroforestry a few years back, and grows cover crops. and a hint : Depleted soils can be protected from soil erosion by groundcover plants such as naturally growing grasses in agroforestry systems. These help to stabilise the soil as they increase cover compared to short-cycle cropping systems. Soil cover is a crucial factor in preventing erosion. Cleaner water through reduced nutrient and soil surface runoff can be a further advantage of agroforestry. The runoff can be reduced by decreasing its velocity and increasing infiltration into the soil. Compared to row-cropped fields nutrient uptake can be higher and reduce nutrient loss into streams.Further advantages concerning plant growth: Please answer this question : Which farmer reduced soil surface runoff from his farm?
Ans: Gary

You are given a new situation: Two different countries produced their electricity using different methods. Burma used fossil fuels such as coal and oil, while Bhutan used renewable energy sources. and a hint : When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure below ). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas , since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earth's temperature, known as global warming or global climate change. Please answer this question : Which country contributed more to a global rise in Earth's temperature?
Ans: Burma