Answer:
Knowing this, researchers from the University of Southern Denmark decided to investigate the size of these hypothetical hidden particles. According to the team, dark matter could weigh more than 10 billion billion (10^9) times more than a proton.
Explanation:
If this is true, a single dark matter particle could weigh about 1 microgram, which is about one-third the mass of a human cell (a typical human cell weighs about 3.5 micrograms), and right under the threshold for a particle to become a black hole.
<u>Answer:</u> The amount of heat released is 56 MJ.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of
= 12 kg = 12000 g (Conversion factor: 1 kg = 1000 g)
Molar mass of
= 30 g/mol
Putting values in above equation, we get:

The chemical reaction for hydrogenation of ethene follows the equation:

By Stoichiometry of the reaction:
When 1 mole of ethane releases 140 kJ of heat.
So, 400 moles of ethane will release =
of heat.
Converting this into Mega joules, using the conversion factor:
1 MJ = 1000 kJ
So, 
Hence, the amount of heat released is 56 MJ.
If you’re talking about noble gases, the answer would be A. Since noble gases already have 8 electrons, they don’t tend to form chemical bonds. And elements need just 8 electrons on there shells to be stable.
Answer:
<u>The temperature difference is</u> 
Explanation:
The formula that is to used is :
Δ
Δ
<em>where ,</em>
- <em>Δ
is the heat supplied in calories = 300cal</em> - <em>
is the mass of water taken = m (assumed)</em> - <em>Δ
is the change in temperature</em> - <em>
is the specific heat of water =
</em>
ΔT :

Answer:
0.5 mole
Explanation:
C=12u
O=16u
1 mole carbon dioxide=44 grams
so 22grams = 0.5 mole