Maria examines a mixture that appears to be the same throughout. however, when she looks at a sample using a magnifying lens, she can see small droplets of liquid surrounded by another liquid. which conclusion best fits her observations? the mixture is a solution because it has the same appearance throughout the sample. the mixture is a suspension because it is composed of two different-appearing substances. the mixture is a heterogeneous mixture because one liquid is dissolved in the other. the mixture is a colloid because two different substances can be seen in a small sample.

The correct statement is the last one.

Explanation:

A microscopically insoluble component, which is suspended all through the other substance is known as a colloid. As the existence of an emulsifying agent, that is, a mixture of water and oil becomes a colloidal dispersion.  

Colloidal dispersion is a system in which the droplets, discrete particles, or bubbles of a dispersed phase (oil) are distributed in the other, generally the continuous phase-dispersion medium (water) varying from the dispersed phase in the state of aggregation or composition.  

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.