Answer:
D or A
<em>But I do know...</em>
It's because new strains of the virus are constantly appearing and evolving, so the vaccine must change along with them.
The ring shape of the Cartwheel Galaxy is due to collisions with another galaxy.
<h3>What causes the ring shape of the Cartwheel Galaxy?</h3>
The unusual shape of the Cartwheel Galaxy is due to a collision with a smaller galaxy. The recent star burst has lighted up the Cartwheel rim which has a diameter larger than that of the Milky Way galaxy in which our planet exists. The Cartwheel Galaxy is a lenticular ring galaxy which is about 500 million light-years away. This galaxy was discovered by Fritz Zwicky in the year 1941.
So we can conclude that the ring shape of the Cartwheel Galaxy is due to collisions with another galaxy.
Learn more about galaxy here: brainly.com/question/13956361
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Answer:
0.88 g
Explanation:
Using ideal gas equation to calculate the moles of chlorine gas produced as:-

where,
P = pressure of the gas = 805 Torr
V = Volume of the gas = 235 mL = 0.235 L
T = Temperature of the gas = ![25^oC=[25+273]K=298K](https://tex.z-dn.net/?f=25%5EoC%3D%5B25%2B273%5DK%3D298K)
R = Gas constant = 
n = number of moles of chlorine gas = ?
Putting values in above equation, we get:

According to the reaction:-

1 mole of chlorine gas is produced when 1 mole of manganese dioxide undergoes reaction.
So,
0.01017 mole of chlorine gas is produced when 0.01017 mole of manganese dioxide undergoes reaction.
Moles of
= 0.01017 moles
Molar mass of
= 86.93685 g/mol
So,

Applying values, we get that:-

<u>0.88 g of
should be added to excess HCl (aq) to obtain 235 mL of
at 25 degrees C and 805 Torr.</u>
1.50x10^6 m2 is the answer you're looking for