Answer:
C
Explanation:
the largest star in the universe
(going from top to bottom)
snake, mouse, seed
bottom to top
seed, mouse, snake
Answer:
Krypton is a noble gas, so it was difficult for chemists to find it, as though it was a secret
Explanation:
Krypton is a noble gas and this demand it has full orbital electron shells (2.8.18.8 or [Ar].3d¹⁰.4s².4p⁶). They, therefore, do not have an affinity for gaining or losing an electron hence rarely react with other elements. They were therefore hard to discover by early chemists because there were no known compounds of this gas and other noble gases. This is why the name ‘hidden’.
Lactase is a protein (enzyme) that speeds up the breakdown of lactose (milk sugar) into the simple sugars (glucose and galactose). Lactase is found in the small intestine of mammals and it is abundant during infancy but declines with age. Lactase is produced by the enterocytes (cells) that covers the intestinal walls and it creates the chemical barrier through which food molecules must cross for absorption by the intestines.