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Answer:</h2>
Chalk is a <u>C) Compound</u>.
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Explanation:</h2>
Element refers to one single substance which is made up of atoms and sub atomic particles namely electron, proton and neutron. A colloid is a blend where one substance of minutely scattered insoluble or solvent particles is suspended all through another substance.
Solution is composed of two components solute and solvent. When elements combine together it leads to the formation of compound. Chalk is considered as compound because, it is a substance formed by fusion of carbon dioxide and calcium hydroxide.
Answer:
D
Explanation:
crossing over is where the homologous chromosomes exchange their genetic material through synapse
Answer:
Ambulacraria
Explanation:
Ambulacraria or Coelomopora is an invertebrate clade that encompasses the Echinodermata and Hemichordata within the deuterostomies. This grouping is considered Chordata's sister taxon because it has a common ancestor.
The phylum Chordata is considered the last within the evolutionary range and comprises all vertebrates and some invertebrates such as amphioxus and tunicates. The main feature of this phylum is the presence of notochord in at least one of its embryonic phases. In vertebrates, the notochord will later make room for the Vertebral Column.
A primary air pollutant is directly from the source and secondary pollutants are omitted from two or more different primary pollutants interact with each other in the atmosphere.
EX of primary: carbon monoxide, nitrogen oxide, sulfur oxid
EX of secondary: NO2 acid rain
