<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: Between 1 and 2.
Explanation:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
............(1)
where,
a = amount of reactant left after n-half lives = 40
= Initial amount of the reactant = 100
n = number of half lives
Putting in the values we get:

taking log on both sides


Thus half-lives that have elapsed is between 1 and 2
Answer:
D) HCl(aq)
Explanation:
A homogeneous mixture can be defined as any liquid, solid or gaseous mixture which has an identical or uniform composition and properties throughout any given sample of the mixture. In Chemistry, all solutions are considered to be a homogeneous mixture.
In this scenario, the chemical formula which represents a homogeneous mixture is aqueous hydrogen chloride, HCl(aq). The aqueous hydrogen chloride is a homogeneous mixture of water and hydrogen chloride. This ultimately implies that, aqueous hydrogen chloride HCl(aq) is a solution of hydrogen chloride in water and it is commonly referred to as Hydrochloric acid.
Given by the chemical equation;
If you have a book, read it!! I promise you, it tells you this answer!