Gravity. The rock is being pushed down and you are counteracting that force with a crowbar pushing it upward.
<em>From the above options, the best </em><em>Thermal insulator </em><em>will be a </em><em>Plastic cup.</em>
Option (b);
<u>Explanation</u>
Thermal insulators resist to conduct energy or reduction of heat transfer when objects come across in contact with radiation or higher heat object. To conduct energy we need metal or those materials which contain free electrons in it to move from one metal to another.
Plastic doesn't have metallic character so it will resist the heat up to some threshold. Mostly this material is used in separating two current-conducting material. There are many other examples of thermal insulator such as Rubber, fabrics, paper, wood, wool.
24. F:H :) because Fluorine is the most electronegative
The given compound is Aluminum sulfate, Al2(SO4)3:
Molar masses:
Aluminum = 27 g/mol
Sulfur = 32 g/mol
Oxygen = 16 g/mol
The total molar mass is 342 g/mol
The ratio by mass of the elements:
Aluminum = 27*2/342
= 0.16
Sulfur = (32*3)/342
= 0.28
Oxygen = (16*12)/342
= 0.56
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Answer:
See the answer below, please.
Explanation:
Take as an example a light bulb inside a lamp to illuminate a room. When you plug it in a plug and turn it on, light is generated. More precisely, heat (Joule effect) is produced inside the lamp by its internal filament (conductive material) when it passes through the electrical energy, generated by the friction of the atoms that are inside it when it encounters a resistance.