Answer:
Four covalent bonds.
Explanation:
Hello,
In this case, given the attached picture in which you can find the Lewis dot structure for metanal (formaldehyde) we can see two C-H bonds and two C-O bonds via a double bond, thus, we can compute the type of each bond given the electronegativities of hydrogen, carbon and oxygen which are 2.1, 2.5 and 3.5 respectively:
Thus, since both electronegativity difference are less 1.7 we infer that all of them are covalent, therefore, it has four covalent bonds, two C-H bonds and a double C-O bond.
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The person who is behind the boat will see much powerful and bigger waves than the person who is in front of the boat. This phenomenon is caused by the Doppler effect which describes the changes in the observed frequency of a wave whenever there is relative motion between the wave source and the observer.
Answer:
The correct answer is - may not be typical, and participant burden.
Explanation:
The 24-hour recall is nothing but a retrospective method of diet assessment. In this method, an individual is interviewed about his or her diet consumption during the last 24 hours.
The disadvantages or limitations of this method include the inability of a single day's intake to describe the typical diet, multiple recalls to intake, cost and administration time; participant burden, have to recall to reliably estimate usual intake.
1. Double replacement (DR)
2. Decomposition (D)
<h3>Further explanation</h3>
1. Al2(SO4)3 + Ca3(PO4)2 -> 2AIPO4 + 3CaSO4
Double replacement (DR) : there is an ion exchange between two ion compounds in the reactant to form two new ion compounds in the product
General form :
AB + CD -> AD + CB
2. 2NaCIO3 → 2NaCl + 3O2
Decomposition (D) : Reactant breakdown into simpler ones(reverse of combination)
General form :
AB ---> A + B
