The reactivity of metals increases as you move left in a period and as you move down in a group, so Marie needs to know the period and group of the element inside each box. Boxes that show locations in groups 1 or 2 or in period 8 contain the most reactive elements.
Note that
The heating value of standard coal is about 30,080 kJ/kg
1 L of water has a mass of 1.0 kg
The mass of 15 L of water = 15 kg.
The latent heat of vaporization of water is about 2260 kJ/kg,
The energy required to boil 15 L of water is
(2260 kJ/kg)*(15 kg) = 33900 kJ
The mass of coal required to provide this energy is
(33900 kJ)/(30080 kJ/kg) = 1.127 kg
Because 1 kg = 2.205 lb, the mass of coal required is
(1.127 kg)*(2.205 lb/kg) = 2.485 lb
Answer: 2.49 lb (nearest hundredth)
Diffusion is the physical process whereby atoms or molecules tend to move from an area of higher concentration or pressure to an area of lower concentration or pressure.
In the field of science, diffusion can be described as a process in which molecules move along the concentration gradient i,e from a region of higher concentration to a region of lower concentration.
The process of diffusion is extremely useful in many everyday living conditions. For example, it is due to diffusion that carbon dioxide and oxygen are exchanged between the lungs and the blood. Diffusion of water, salts, and water is an important process that occurs in the kidneys.
We can divide diffusion into two main types which are simple diffusion and facilitated diffusion. Simple diffusion occurs without any carrier molecule. On the other hand, facilitated diffusion occurs with aid of a carrier molecule.
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They are different elements. However, most of their chemical properties are similar, because of the similar numbers of electrons in their valence shells. Their physical properties differ because of the mass contained in the atoms of <span>each element.</span>
The primary role of carbohydrates is to supply energy to all cells in the body. Many cells prefer glucose as a source of energy versus other compounds like fatty acids. Because the energy from glucose comes from the chemical bonds between the carbon atoms.