Answer:
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Explanation:
Answer:
10. mol NaOH
Explanation:
2.5 M = 2.5 mol/L
2.5 mol/L * 4 L = 10. mol
Döbereiner grouped the known elements into <em>triads</em> (sets of three) so that
• The <em>atomic mass of the middle element</em> was approximately the average of the other two
• The <em>chemical properties of the middle element</em> were between those of the other two
• The <em>physical properties of the middle element</em> were between those of the other two
One example of a triad is Li – Na – K.
(a) Atomic mass of Na = 23.0 u
Average atomic mass of Li and K = (6.9 u + 39.1 u)/2 = 46.0 u/2 = 23.0 u
(b) Li reacts slowly with water. Na reacts rapidly. Potassium reacts violently.
(c) Melting point of Na = 371 °C.
Average melting point of Li and K = (454 °C + 330 °C)/2 = 784 °C/2
= 392 °C
In a food chain we arrange the energy in the form of a pyramid.
The producers are on the base of pyramid and then consumers are towards peak.
in the given food chain grass is being eaten by grasshopper which are food of birds.
Grasshoppers are also eaten up by Hawks. so both brids and hawks are feeding upon grasshoppers thus the amount of energy transferred from the grass to the grasshopper is the same as the amount of energy transferred from the grasshopper to the bird.
Extreme weather e.g. snow and cold weather. Another main contributing factor is that many places have a long dry season.