All elements have a AHf, of <u>0</u>
kJ/mole at standard temperature and pressure.
<h3>What is an element?</h3>
An element can be defined as a substance which cannot be split into two or more simpler forms by an ordinary chemical process
Below are the list of the first twenty elements:
- Hydrogen
- Helium
- Lithium
- Berylium
- Boron
- Carbon
- Nitrogen
- Oxygen
- Fluorine
- Neon
- Sodium
- Magnesium
- Aluminum
- Silicon
- Phosphorus
- Sulphur
- Chlorine
- Argon
- Potassium
- Calcium
So therefore, all elements have a AHf, of <u>0</u>
kJ/mole at standard temperature and pressure.
Learn more about elements:
brainly.com/question/11829854
#SPJ1
its exothermic. exothermic means the reaction gives out heat. [exo meaning outside and thermic meaning heat] because its a combustion reaction, fire is there meaning lots of heat.
endothermic means it takes in heat. a good example is ammonium and water (NH3 +H20)
<span>most chemical reaction are exothermic</span>
Answer:
Identify the flaw in the way Maria set up her experiment.She did not take pictures.pictures.She She did did not not wait wait long long enough.enough.She She did did not not measure measure the the temperature.temperature.She She did did not not mix mix the the substances substances well well enough.enough.
your welcome :p
Answer:
Please find the complete question in the attached file.
Explanation:
It would only be radioactive if the DNA molecule that employed the poly-T rand as templates. Its other molecule of the daughter would not have been radioactive as it did not need dATP for its replication. While each strand of the second molecule includes t, simultaneous reproduction dATP from both daughter molecules is needed so that each of those is radioactive.
Jupiter's atmosphere is composed predominantly of hydrogen and helium, but if you have to select any one option then we can look at the percentage of existence of these elements that would be
<span>90 percent hydrogen.
remaining 10 percent is helium
so choose Hydrogen.</span>
