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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If from the low tide to the high tide there was a break of 6h and 4m than the next tides will happen at the same rate:
8:35 + 6:04 = 14:39 = next low tide.
14:39 + 6:04 = 20:43 = next high tide.
Note that two same tides occur about 12h to 12h and 25m apart, and that is the case here:
14:39 - 2:31 = 12:08 hours apart
20:42 - 8:35 = 12:07 hours apart.
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Invasion and multiplication of pathogenic microorganisms<span> in the body is called an infection. When we are infected by </span>pathogens<span> we become sick, which means that our bodies stop functioning properly. Infectious agents, such as </span>bacteria<span>, a virus, fungi or protozoa cause communicable diseases.</span>
Answer:
c. saltatory conduction
Explanation:
An electrical impulse begins at the upper end of the neuron. This area is known as the axon ridge, and this ensures that the electrical impulse will travel in one direction only.
Through the myelin, the electrical impulse jumps from one node to another, instead of having to travel the entire distance from the axon. This type of signal conduction is called saltatory conduction.
Saltatory conduction speeds up impulse movement, as some axons may be up to one meter long. With this, the body achieves fast and efficient nerve conduction, and it is what allows you to react so quickly during reflexes.
