Answer:
In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomic mass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.
Explanation:
Answer:
the conversion of matter into energy
Explanation:
A nuclear reaction is a reaction in which there is a change in the nuclei of the atoms involved. The two most important examples of nuclear reactions are:
- Nuclear fission: it occurs when a heavy, unstable nucleus breaks apart into two or more lighter nuclei
- Nuclear fusion: it occurs when two lighter nuclei fuse together into a heavier nucleus
In both cases, the total mass of the final products is smaller than the total mass of the initial nuclei: this means that part of the mass of the initial nuclei has been converted into energy, according to Einstein's formula:
where 
is the variation of mass and c is the speed of light. Since the value of c is very large, we can see from the formula that even a small amount of is able to produce a huge amount of energy, and this is a typical feature of any nuclear reaction.
<span>Plasma Basics. Plasmas are a lot like gases, but the atoms are different, because they are made up of free electrons and ions of an element such as neon (Ne). You don't find naturally occurring plasmas too often when you walk around. They aren't things that happen regularly on Earth.</span>
Answer:
time spent = 0.2276
Explanation:
given data
distance = 135 mi
usual speed = 65 mph
today speed = 73 mph
solution
we get here time that is express as
time = 
...................1
usual time = 
= 2.0769 h
today time = 
= 1.8493 h
so we get here time spent as
time spent = 2.0769 h - 1.8493 h
time spent = 0.2276
Answer:
A sleep researcher will use EEG to monitor a sleeping person's brain waves.
Explanation:
EEG stands for 'Electroencephalogram'. The EEG test is done to track and record brain wave patterns. Electrodes are placed on a person's brain scalp which detects brain signals and send it to a computer which shows the brain waves pattern. A researcher or a doctor can compare it to the pattern of waves of a normal brain and look for abnormalities to detect a special condition or disease.
EEG is used to find problems related to electrical activity of the brain. It is usually done to diagnose and monitor seizure disorders. Also, to observe brain activity in case of sleeping disorders or change in behavior.
