The one that is true is the last one that you listed
"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:
Eukaryotic photosynthetic colonial organism
Explanation:
According to the given information, the cell of the organism has membrane-bound organelles such as mitochondria and chloroplasts. The presence of membrane-bound organelles in cells is the characteristic feature of eukaryotic organisms.
The presence of chloroplasts in the cells makes the given organism photosynthetic. Chloroplasts are the double membrane-bound organelles and serve as site for photosynthesis.
Many identical cells of a colonial organism are stick together to form different shapes. Since 70 cells are found joined together, the given organism is colonial.
The appropriate answer is D. Alfalfa. Alfalfa is a legume and these plants play a key role in the nitrogen cycle. These plants house nitrogen fixing bacteria on their roots. The bacteria are housed in tiny round structures of leguminous plant roots. Once the nitrogen is fixed in the soil it can now be used by other plants to make food. These plants include beans peas and peanuts. <span />
