An unknown brown solid material was melted and then allowed to cool. it did not separate into different substances. is the unknown material a mixture or a pure substance?

i think the unknown solid is

Which statement best describes the relationship between an allele and a gene? question 1 options: an allele is a variation of a gene that can be expressed as a phenotype. an allele is the part of a gene that attaches to messenger rna molecules. an allele is a segment of a dna molecule that controls replication of a gene.

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?

Which of the following is a good strategy when it comes to desserts