"These" should be referring to Alkali Metals.
They include metals such as Lithium, Sodium, Potassium etc.
They're classified as Group I elements because they all have one outmost shell electrons. This is why these metals are so reactive because they only need to lose one electron in order to achieve the octet of electrons (or duplet for Lithium), which means complete outmost shell electrons (2 or the 1st shell, others are 8).
The reason why they're especially reactive to Halogens (Group VII) elements are that Halogens have 7 outmost shell electrons, which only needs one more electron in order to get to the octet of electrons. So, if an Alkali metal reacts with a Halogen, the metal would give one of their electrons to the Halogen, that way, both of the elements can have an octet of electrons (or duplet).
Answer:
I think u right. it's what I woulda picked
Answer: hopefully this helps? :)
Explanation:The base pairs are stabilized by hydrogen bonds; adenine and thymine form two hydrogen bonds between them, whereas cytosine and guanine form three hydrogen bonds between them. Figure 7. Hydrogen bonds form between complementary nitrogenous bases on the interior of DNA
I believe the answer to your question is C, correct me if i'm wrong :)
It is relative dating because no scientist can tell the actually time that the layers of rocks where formed or when the fossil began to degrade
