- A beam of electrons has.....
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Answer:
Explanation:
To convert from atoms to grams, you must first convert atoms to moles, then moles to grams.
1. Convert Atoms to Moles
To convert atoms to grams, Avogadro's number must be used.
This number tells us the number of particles (atoms, molecules, ions, etc.) in 1 mole. In this case, the particles are atoms of iodine.
Multiply the given number of atoms by Avogadro's number.
Flip the fraction so the atoms of iodine will cancel out.
Multiply so the problem condenses into 1 fraction.
2. Convert Moles to Grams
Now we must use the molar mass of iodine, which is found on the Periodic Table.
- Iodine Molar Mass: 126.9045 g/mol
Use this mass as a fraction.
Multiply this fraction by the number of moles found above.
Multiply. The moles of iodine will cancel.
The 1 as a denominator is insignificant.
3. Round
The original measurement of 1.76*10^23 has 3 significant figures (1, 7, and 6). Therefore we must round our answer to 3 sig figs. For this answer, that is the tenths place.
The 8 in the hundredth place tells us to round the 0 up to a 1.
There is about <u>37.1 grams of iodine </u>in 1.76*10^23 atoms.
Explanation:
- Evaporation is defined as a process in which liquid state of water is changing into vapor state.
So, we need to break the bonds of liquid substance in order to convert it into vapor state. And, energy is absorbed for breaking of bonds which means that evaporation is an endothermic process.
Hence, the statement evaporation of water is an exothermic process is false.
- When a hydrocarbon reacts with oxygen and leads to the formation of carbon dioxide and water then this type of reaction is known as combustion reaction.
A combustion reaction will always release heat energy. Hence, combustion reaction is exothermic in nature.
- When energy is transferred as heat from the surroundings to the system then it means energy is being absorbed by the system. And, absorption of heat is an endothermic process for which
is positive.
- Whereas when energy is transferred from system to the surrounding then it means energy is released by the system which is an exothermic process.
Hence, for an exothermic process value of is negative.
Thus, we can conclude that statements which are true are as follows.
- A combustion reaction is exothermic.
- When energy is transferred as heat from the system to the surroundings,
- For an endothermic reaction Deta H is positive.