Answer:
- <em>The coefficients in a chemical equation represent the </em><u>relative number of moles of each reactant and product that interven in the chemical reaction.</u>
Explanation:
The <em>coefficients</em> are the numbers that you put in front of each chemical formula that represents the reactants and products in the <em>chemical equation</em>. They indicate the mole ratio in which the elements or compounds react to form the products, as per the chemical equation.
See an example:
- Word equation: hydrogen and oxygen produce water
- Chemical (skeleton) equation: H₂ (g) + O₂(g) → H₂O (g)
This equation is not balanced: the number of atoms of oxygenin the reactant side is 2 while the number of atoms of oxygen isn the product side is 1. In order to balance the equation you need to add some coefficients.
When no coefficients are shown it is understood that the coefficient is 1.
- Balanced chemical equation: 2H₂ (g) + O₂(g) → 2H₂O (g)
The coefficients 2 in front of H₂ and 1 (understood) in front of O₂, in the reactant side, and 2 in front of H₂O, in the product side, balance the equation.
Those coefficients mean that the 2 molecules (or mole of molecules) of H₂ react with 1 molecule (or mole of molecules) of O₂ to form 2 molecules (or moles) of H₂O (product side).
That is the mole ratio: 2 H₂ : 1 O₂ : 2 H₂O.
Notice that, in spite of the aboslute numbers may change, the mole ratio is unique for any chemical reaction. For example 4 : 2 : 4 is the same ratio that 2 : 1 : 2, or 8 : 4 : 8, but the most common practice is to use the most simple form of the ratio, i.e. 2: 1: 2.
Answer 1) Option D : Discrete
Explanation : As in the example the scientist studies about the effects of growing human populations on the biodiversity which is found in a region, and where each region was selected had a different population density of humans from 1 to 10 million per 10 square miles. Then in each region the number of different species that can be found was recorded. So here the numerical data was collected for different regions. So, we can conclude it as discrete because when the variable takes on a countable number of values it is called as discrete.
Answer 2) Option D : The entertainment industry
Explanation : When people had enough time and money with them there was no need of creating the communications industry as it was a need not a luxurious thing. With the creation of Internet industry it is somewhat irrelevant. They had enough of time and money so building a labor industry seems to be a lame choice. So, the option of entertainment industry suits the best.
Answer:
2Fe(s) + 3O2(g) --------> 2FeO3(s)
Explanation:
According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.
Iron reacts with oxygen under these conditions as follows;
2Fe(s) + 3O2(g) --------> 2FeO3(s)
This is the chemical reaction that occurs when the steel wool is set on fire.
Answer:
Cell membrane and cytoplasm
Explanation:
Cell membrane is the layer that surronds the cell and it is made up of lipids and proteins. It is made up of a kind of fatty acids based lipids i.e phospholipids and sterols.
Cytoplasm is a thick fluid that is found in the cell membranes. It acts as buffer and protect cells organelles and DNA from damage. It is made up of water, p, lipids, proteins, inorganic salts, nucleic acids.
