<span>There are two major theories that will explain on research on colour vision. They are 1. the trichromatic theory also known as the Young-Helmholtz theory 2. opponent-process theory. These two theories explain processes that operate at different levels of the visual system.</span>
Answer: Addison disease is an adrenal insufficiency. This occurs because of the fact that adrenal gland produces very low quantity of hormones like cortisol, and aldosterone.
Explanation:
1. The symptoms of addison disease are loss of appetite, increased thirst, low mood, and muscle fatigue.
2. The addison disease is an autoimmune reaction, which can affect people of all age groups.
3. It can cause other diseases like tuberculosis.
4. The hormone replacement therapy is ideal for the treatment for addison disease. The use of oral corticosteroids is ideal. The diet containing balanced proteins, carbohydrates, fats, increased intake of vegetables including vitamins, and minerals are necessary for treatment of addison disease.
B. Effective against all pathogens
Answer:
The elements in increasing order of atomic radius: oxygen, carbon, aluminum, potassium
Explanation:
The distance from the center of the nucleus to the outermost shell of the electron is known as the atomic radius of an element. The atomic radius decreases rightward along each period (row) of the table due to the increase in effective nuclear charge (the charge of the nucleus equal to the number of protons). Across a period, electrons are added to the same energy level and the increasing number of protons causes the nucleus to exert more pull on these electrons, which makes the atomic radius smaller. Atomic radius increases down each group (column) of the periodic table because of the addition of electrons to higher energy levels, which are further away from the nucleus and the pull of nucleus weakens. Another reason for the increase in atomic radius is the electron shielding effect, which is the reduction of the attractive force between a nucleus and its outer electrons due to the blocking effect of inner electrons
While moving from left to right in the second period, c
arbon comes before oxygen and so oxygen will have a smaller atomic radius than carbon. While moving down the periodic table, al
uminum comes before potassium even if they are not in the same period. So aluminum
's atomic radius will be smaller than that of potassium but bigger than that of carbon and oxygen.
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The three substances that cause a double displacement reaction to occur are:
(i) Ionized compounds. These are usually water.
(ii) A gas that bubbles out a solution.
(iii) A precipitate.
In double displacement reaction is where two new compounds are formed when two parts of two compounds switch places. For example; when sodium chloride combines with silver nitrate, the two new compounds formed are Sodium nitrate and silver chloride reason being sodium and silver switched places.
