i think it has to do with how old it looks, because a star starts off as a baby little star, a different color and size. its also in a nursery with a lot of other stars, which is called a nebula. as the stars grow older and larger, they change color and drift apart. the scientists must've seen that the star has a totally different color from the baby ones, way brighter and much larger, also seeing that stars grow apart, it has not really many stars living around it for miles and miles. they must've guessed that it was probably really old.
Answer:
Because of the chemical and structural nature of the phospholipid lipid by layer the lipid soluble molecule can just pass the lipid membrane and some small molecules can also pass freely.
Explanation:
as we know that the homeostasis is an important process for a living cell to maintain it self so for the the exchange of materials between the external and internal environment is must so for that it exchange material with the outside environment of the cell.as the cell membrane is semipermeable(mean allow some molecule to pass(lipid soluble) and not others(lipid non soluble) to pass through the membrane.the cell membrane is selectively permeable due to its nature and chemical composition the chemical composition is lipid and phosphate and glycerol(head) with fatty acid that may b saturated or unsaturated(tail).so finally all those molecule which are polar can not pass through the membrane and non polar can pass the membrane.The size of the molecule is also a factor on which the permeability depends.
Answer:yes
Explanation:
Impure substance is a mixture of 2 or more molecules
