Which of the following is a homogenous mixture of two or more pure substances?
a. water
b. air
c. alcohol
d. oxygen

#2: you run a chromatogram of inks belonging to three crime suspects and from a ransom note. the inks resolve into the following numbers of spots: suspect a = 2, suspect b = 4, suspect c = 3, note = 5.

which suspect would you most likely bring in for questioning?

a. suspect a

b. suspect b

c. suspect c

d. none of the suspects

1. The answer to this question would be air.
Air contains oxygen, nitrogen, carbon dioxide so it was a mixed one. The other option is a compound(water, alcohol) or molecule(oxygen) so it's not a mixture.

2. The answer to this question would be D. none of the suspects.
Since the note is 5 spots so there is no match for the suspect. But if you looking for the most suspicious then it could be suspect B with 4 spot which was near 5

1. Air is a homogenous mixture of two or more pure substances. Air is a mixture of many gases and dust particles

Water and alcohol are compounds, while oxygen is an element

Further explanation

A single substance can be an element or compound. The element is a single substance that cannot be broken down anymore or the simplest substance.

While the compound is a single substance that is formed from a combination of two or more through chemical reactions and has a fixed ratio.

The mixture is a combination of two or more substances whose constituent properties do not change. The properties of the mixture component are not lost / unchanged as in compounds.

The mixture can be divided into a homogeneous mixture if the composition/ratio of each substance in the mixture is the same and heterogeneous mixture if the ratio of the composition of the substances is not the same in each place.

Mixtures can also be divided into solutions, suspensions, and colloids based mainly on the size of the particles

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2. D. none of the suspects that will be brought to be asked questions

Further explanation

Chromatography is one technique for separating mixtures into its constituent components based on the principle of stationary and mobile phases.

Generally used to separate ink is paper chromatography. Where the stationary phase is paper and the mobile phase is solvent/sample. The ink on the pen is a mixture of several dyes. The absorbed solvent will separate the ink dye into several spots that indicate the constituent components of the dye from the ink

The statement of the question states that the ink from the notes shows 5 spots while the ink from the suspect's pen is only 2 spots (suspect A), 4 spots (suspect B) and 3 spots (suspect C)

Thus there is no match, but that approaches the number 5 spots of the ink note is suspect B with 4 spots

Learn more

A heterogeneous mixture

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a homogeneous mixture

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Paper Chromatography

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Keywords: a homogeneous mixture, Paper Chromatography

The  grandmother cell  is a hypothetical  neuronthat represents a complex but specific concept or object.[1]  it activates when a person "sees, hears, or otherwise sensibly discriminates"[2]  a specific entity, such as his or her grandmother. the term was in use at least as early as 1966 amongst staff and students in the department of experimental psychology, university of cambridge, england. a similar concept, that of the  gnostic neuron, was proposed two years later

Iwould you figure it out but you don't have a picture or in your question as to what the physical property you're looking for is