The two are potassium and rubidium. Why? Na is an alkali metal. As you go down the metals become more reactive.
Calcium has 20 protons. Why? The atomic # is 20 (the one at the top).
It has 20 neutrons. Why? The atomic mass (the number on the bottom) is ~40, ignoring electron mass. 40- 20 protons = 20 neutrons.
It has 20 electrons.
Why? The # of protons and electrons is the same. Ions aren't on the periodic table.
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Cast- solid copy
Mold- hollow form
Carbon film- details left after an organism decays
Trace fossil-record of an organisms activity
Petrified fossils- living things turned into rock
Answer:
Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction.
Explanation:
Embryonic stem cells can become all cell types of the body because they are pluripotent. Adult stem cells are thought to be limited to differentiating into different cell types of their tissue of origin. Embryonic stem cells can be grown relatively easily in culture.
Answer:
Lysozyme in the body fluid protects us from bacterial infection by damaging the cell wall of bacteria which ultimately kills the bacteria.
The bacterial cell wall is made up of NAG and NAM units which is joined by β (1-4) glycosidic bond. Lysozyme attacks on this bond and breaks it causing the damage in the cell wall of bacteria which leads to the death of bacteria.
Archaeal cell wall do not contain β (1-4) glycosidic linkage, it contains β(1-3) glycosidic linkage in its cell wall between NAT and NAG unit and lysozyme do not able to break β(1-3) glycosidic linkage between them so lysozyme do not cause any harm to the archaeal invaders.
