Answer the following question given this paragraph: The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are "eager" to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table. Alkali metals have just one valence electron, which they are equally "eager" to donate. Reactions involving halogens, especially halogens near the top of the group, may be explosive. You can see some examples in the video at the URL below. ( Warning: Don't try any of these reactions at home!). Q: In which order does the reactivity of halogen group decline? Choices: - bottom to top - right to left - left to right - top to bottom A:
top to bottom
(Question)
Answer the following question given this paragraph: Q: What structures on the gastrodermal cells keep the contents of the gastrovascular cavity agitated and help distribute nutrients? Choices: - telomeres - sporangia - nucleus - flagella A:
(Answer)
flagella
Ques: Answer the following question given this paragraph: Q: What is it in bone marrow transplants that may cause a graft versus host reaction? Choices: - tumors - neutrophils - cancer - lymphocytes A:
Ans: lymphocytes
(Q).
Answer the following question given this paragraph: Q: Freezing rain that falls from the sky is also called? Choices: - snowfall - hail - fog - sleet A:
(A).
sleet
Ques:Answer the following question given this paragraph: Q: Habitat loss, introduced species, overharvesting, and global change are major threats to what? Choices: - the earth's gravity - the sun - transportation - biodiversity A:

Ans:biodiversity
Answer the following question given this paragraph: To begin mitosis, the DNA in the nucleus wraps around proteins to form chromosomes . Each organism has a unique number of chromosomes. In human cells, our DNA is divided up into 23 pairs of chromosomes. Replicated DNA forms a chromosome made from two identical sister chromatids , forming an "X" shaped molecule ( Figure below ). The two chromatids are held together on the chromosome by the centromere . The centromere is also where spindle fiber microtubules attach during mitosis. The spindles separate sister chromatids from each other. Q: What forms when the dna in the nucleus wraps around proteins? Choices: - rna - genes - ribosomes - chromosomes A:
chromosomes