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3 years ago

BRIANLIESTTT ASAP!!! PLEASE HELP ME :)

Chemistry

2 answers:

Volgvan3 years ago

7 0

Answer:

Its reliability is confirmed by many scientists.

Explanation:

hey there,

< Science can't always be confirmed; there are always new rules coming in. Like when they removed Pluto as a planet. >

Hope this helped! Feel free to ask anything else.

Genrish500 [490]3 years ago

4 0

Answer:

Its reliability is confirmed by many scientists

Explanation:

The science and the pseudoscience have multiple differences that separate them clearly and sharply. The science, doesn't matter about scientific field we are talking about, is confirmed by numerous scientists. In order for something to be accepted in the scientific circles as a science, the particular thing in question undergoes numerous studies, from numerous different scientists or scientific groups. If all of the results of all of the studies are confirming the same thing, that it can be accepted as science.

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Determine if each of the following statements about chiral molecules is True or False and select the best answer from the dropdo

oee [108]

Answer:

See explanation

Explanation:

-) True or False: All R stereocenters are dextrorotatory.

The absolute configuration is based is in specific rules that are not related to the ability to deflect polarized light. FALSE

-) True or False: Chiral centers in organic molecules will have 4 different groups attached to a carbon.

A chiral carbon by definition is a carbon with 4 groups. TRUE

-) True or False: A racemic mixture has an optical activity of 0.

In a racemic mixture, we have equal amounts of enantiomers, and this cancels out the optical activity. TRUE

-) True or False: Normal linear amines can be chiral centers.

In primary amines, we have 2 hydrogens. Therefore all the groups can not be different. So, is TRUE

-)True or False: Compound C has an optical activity of 0.

We need to know the structure of the compound

-)True or False: If the R isomer of a molecule has an optical rotation of + 25.7 degree then the S isomer of the molecule will have an optical rotation of -25.7 degree.

If we have the exact opposite (as we have in this case) the magnitud of the optical activity value will remain and the sign will change. TRUE

-)True or False: A CN is a higher priority than a CH2OH.

In this case, a carbon is directly bonded to the chiral carbon. The carbon on CN is bonded to a nitrogen atom and the carbon on CH2OH is bonded to an oxygen. So, the CH2OH will have more priority because O has a higher atomic number. FALSE

-)True or False: All molecules with chiral centers are optically active.

We can have for example mesocompounds in which the optical activity is canceled out due to symmetry planes. FALSE

-)True or False: To have an enantiomer a molecule must have at least two chiral centers.

A pair of enantiomers is made between at least 1 chiral carbon. Enantiomer R and enantiomer S. FALSE

-)True or False: Chiral molecules are always optically active.

We can have racemic mixtures or mesocompounds with chiral carbons but without optical activity. FALSE

-)True or False: A CH2CH2Br is higher priority than a CH2F.

The "Br" atom is bonded in the third carbon (respect to the chiral carbon) and the "F" atom is bonded to the second carbon. Therefore CH2F has more priority than CH2CH2Br. FALSE

-)True or False: Meso molecules with two stereocenters have a R,S configuration.

On the compounds with R and S configuration at the same time can have symmetry planes so, we will not have optical activity. TRUE

True or False: Diastereomers have the same physical properties except in a chiral environment.

All diastereomers have the same physical properties. TRUE

True or False: Compound H has an optical activity of 0.

We have to have the structure of the compound.

True or False: A C=C double bond is higher priority than a -CH(CH3)2.

In the case of C=C, we can say that is equivalent to two carbon bonds without hydrogens. Therefore C=C has higher priority. TRUE

6 0

3 years ago

I need an answer ASAP

Oduvanchick [21]

Time taken for star to reach Earth = 7.5 years

<h3>Further explanation</h3>

Given

7.5 light years(distance Earth-star)

Required

Time taken

Solution

Speed of light=v = 3 x 10⁸ m/s

1 light years = 9.461 × 10¹⁵ m= distance(d)

So time taken for 1 light years :

time(t) = distance(d) : speed(v)

t = 9.461 × 10¹⁵ m : 3 x 10⁸ m/s

t = 3.154 x 10⁷ s = 1 years

So for 7.5 light years, time taken = 7.5 years

8 0

3 years ago

Glycogen ________. Glycogen ________. forms the regulatory molecules known as enzymes serves as a structural component of human

jasenka [17]

Answer:

Glycogen in an important storage polysaccharide found in animal tissues.

Explanation:

Full question:

Glycogen ________

A) forms the regulatory molecules known as enzymes

B) serves as a structural component of human cells

C) helps to protect vital organs from damage

D) is an important storage polysaccharide found in animal tissues

E) contains the genetic information found in cells

Glycogen is a complex polysaccharide of glucose founded in humans, animals, fungi and even bacteria. In humans, the glycogen is made and stored in liver cells. In the center on glycogen molecule, there is a single protein called Glycogenin. It is a center of a big flower made of glucose molecules (please refer to the scheme attached - Glycogenin is red and the blue lines are glucose chains). Glycogen is also stored in skeletal muscle, red and white blood cells, in glial brain cells and kidneys but in a smaller amounts. It can be found in the placenta in pregnant women where it serves as a nutrient storage for embryo. In an adult, the liver weighs 1,5 kg and glycogen weighs about 120g in such a liver. After a meal, the level of sugar is rising and the insulin is being secreted. Insulin is a tool by which sugar is being delivered to the cells, like a food delivery. During this period, glycogen is being synthesized in the liver out of glucose residues. When the meal is digested, the sugar level is back to normal. When more energy is needed, glycogen from the liver is broken down by glycogen phosphorylase and the new sugar is released into the bloodstream.

7 0

3 years ago

Metric prefix name for 1/100 ?

babymother [125]

The metric prefix name for 1/100 is centimeters.

5 0

3 years ago

How does the arrangement of elements in periods relate to electron configuration

VashaNatasha [74]

Electronic Configuration of elements in a period is same because If you see the electronic Configuration of elements in a period you will notice that the valence shell electrons for all elements are present in the same Shell. For example, in first period consisting of Hydrogen and Helium, both the elements' valence electrons are present in the same Shell.
Electronic Configuration of Hydrogen,
1s^1
Electronic Configuration of Helium,
1s^2

Both elements' valance electrons are present in the 1st shell

(This is just a small example to understand the concept because other periods are long but the first period is short that's why I gave the example of the first period)

4 0

3 years ago