answer:
in plants
Transport manufactured food from the leaves to others parts of the plant
Facilitates gaseous exchange through the stomata in the leaves to other parts of the plant
in animal
Exchange of respiratory gases across respiratory services
Excretion of nitrogenous waste in some unicellular organisms
Explanation:
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I think the correct answers are X2Y and X3Y, X2Y5 and X3Y5, and X4Y2 and X3Y,
for the following reason:
If you look at the combining masses of X and Y in
each of the two compounds,
The first compound contains 0.25g of X combined with
0.75g of Y
so the ratio (by mass) of X to Y = 1 : 3
The second compound contains 0.33 g of X combined with
0.67 g of Y
so the ratio (by mass) of X to Y = 1 : 2
Now, you suppose to prepare each of these two
compounds, starting with the same fixed mass of element Y ( I will choose 12g
of Y for an easy calculation!)
The first compound will then contain 4g of X and 12g
of Y
The second compound will then contain 6g of X and
12g of Y
<span>The ratio which combined
the masses of X and the fixed mass (12g) of Y
= 4 : 6
<span>or 2 : 3 </span>
So, the ratio of MOLES of X which combined with the
fixed amount of Y in the two compounds is also = 2 : 3 </span>
The two compounds given with the plausible formula must therefore contain
the same ratio.
The rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
<h3>Rate of reaction</h3>
The rate of a chemical reaction is the rate at which the concentration of reactant molecules decreases or the concentration of product molecules increases.
<h3>Factors effecting rate of chemical reaction </h3>
The factors that affect the rate of chemical reaction include:
- Temperature: increase in temperature increases reaction rate while decrease in temperature decreases reaction rate.
- Catalysts: the present of catalysts increase the reaction rate. Some catalysts decreases reaction rate and are known as negative catalysts.
- Surface area: increase in surface area of reactants increases reaction rate.
- Concentration: Increase in concentration of reactants increases reaction rate while decrease in concentration of reactants decreases reaction rate.
Therefore, the rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
Learn more about rate of reaction and factors affecting reaction rate at: brainly.com/question/15841605
Electronegativity of boron is the highest in the group and it will form covalent bonds in all his combinations.
The rest of the group will form bonds with intermediate nature between covalent and ions bods in their respective compounds, with thallium (Tl) behaving most close to a metal.
Moreover boron have a very high melting points (around 2200 °C) while in the boron cristal the chemical bonds are directed in space, similar with carbon suggesting his nature as a non-metal.
Other elements form the group Al, Ga, In, Tl have lower melting points 660, 30, 157 and 304 °C, respectively. Also in the elemental state, they have metallic characteristics: metalic luster, ductility, high electrical and thermal conductivity.
