Answer:
Because it is closer to earth than the other blue giant stars.
Explanation:
The sun is closer to earth than any other big star which means we see it bigger.
<span>1) </span><span>What is air pressure? (Answ</span>er: Atmospheric
pressure, sometimes also called barometric pressure, is the pressure within the
atmosphere of Earth.)
<span>2)
</span><span>What
is a barometer and what is it used to measure? <span>(Answer: A barometer is a scientific instrument used in meteorology to
measure atmospheric pressure. Pressure tendency can forecast short term changes in the
weather.)</span></span>
<span>3)
</span><span>How
does air pressure change? <span>(Answer: Millibar values used in
meteorology range from about 100 to 1050. At sea level, standard air pressure in millibars is
1013.2. Weather maps showing the pressure at
the surface are drawn using millibars. ... This change in pressure is
caused by changes in air density, and air density is related to
temperature.)</span></span>
<span>4) </span><span>Why is cooler, drier air related to High
Pressure? <span>(Answer: This is due to density differences
between the two air masses.
Since stronger high-pressure systems contain cooler or drier air, the air mass is denser and flows
towards areas that are warm or moist, which are in the vicinity of low pressure areas in advance of
their associated cold fronts.)</span></span>
<span>5)
</span><span>Why
is warm, moister air related to Low Pressure?
<span>(Answer: When air warms, its molecules scatter.
The air becomes
lighter and rises.)</span></span>
Answer:
C. Lose three electrons to have a full outer shell
Explanation:
Al is in Group 13 of the Periodic Table, so it has three valence electrons.
It must either lose three electrons or gain five to achieve a stable octet.
It is easier to lose three electrons than it is to gain five, so Al loses three electrons.
D. is wrong, for the same reason.
A. is wrong. If Al lost three electrons, it would be breaking into a stable inner shell.
C. is wrong. Al is a metal, so it will lose electrons in a reaction.
Answer:
(b) Both have the same number of valence electrons.
Step-by-step explanation:
We find the most striking chemical similarities between two Main Group elements when they are in the same Group of the Periodic Table.
Elements in the same Group have the same number of valence electrons.
(a) is <em>wrong</em>, because elements in the same group have <em>different masses</em>.
(c) is <em>wrong,</em> because atoms with the same number of protons belong to the s<em>ame element</em>.
(d) is wrong, because elements in the same Group must be in .
<em>different Periods.</em>
