The answer is A, biogeochemical cycles.
Answer:
The answer to your question is: letter A
Explanation:
A combination reaction is when there are two reactants that gives only one product.
a. 2SO2 + O2—> 2SO3 This is a combination reaction,
2 reactants gives one product.
b. Zn + Cu(NO3)2–>Zn(NO3)2 + Cu This is not a combination reaction,
it's a single replacement reaction.
c. 2H2O2–> 2H2O+O2 This is a decomposition reaction
d. AgNO3 + NaCl → AgCl+NaNO3 THis is a double replacement reaction.
Answer:
- <em>The net charge of the ionic compound calcium fluoride is </em><u><em>zero (0).</em></u>
<em>Explanation:</em>
<em>Ionic compounds,</em> such as covalent ones, have zero net charge; this is, they are neutral.
Substances with net positive charge are cations and substances with net negative charge are anions.
The charges in the <em>ionic compound calcium flouride</em> are distributed in this way:
- Calcium charge: Ca²⁺: this is, each calcium ion has a 2 positive charge
- Fluoride charge: F⁻: each fluoride ion has a 1 negative charge.
- Then, the <em>net charge</em> is: 1 × (2+) + 2 × (1-) = +2 - 2 = 0.
So, a two positve charge, from one calcium ion, is equal to two negative charges, from two fluoride tions, yielding a <u>zero net charge</u>.
Answer:
isomers
Explanation:
Compounds that have the same molecular formula but different chemical structures are called isomers. Remember isomerism is a property between a pair (or more) of molecules, i.e. a molecule is an isomer of another molecule.
Answer:
E) 0.90
Explanation:
In TLC (Thin-Layer-Chromatography) retention factor RF is defined as the ratio between distance of the sample and the solvent front. RF is very important in chemistry to know the composition of any sample by comparison.
In the problem, as the sample has a distance of 0,20cm from the solvent front, the distance of the sample is:
2,0cm - 0,20 cm =<em> 1,8 cm</em>. Thus, RF is:
RF = 1,8cm / 2,0cm = 0,90
<em>E) 0,90</em>
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I hope it helps!
