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Alex73 [517]
3 years ago
15

Need help with 7,9 and may you check my answer for 8 to ?

Chemistry
2 answers:
fomenos3 years ago
8 0
8 looks right to me but not 100%
steposvetlana [31]3 years ago
7 0
Number 9 is C because they are the same element but different numbers. Number 8 is B because they are isotopes of each other, and isotopes have varying number of protons (that’s what make them isotopes of each other.) Number 7 is B.
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Steps of scientific inquiry?
vlabodo [156]
1. Figure out a problem
2. Research
3. Hypothesis  
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Hope This Helps. :D <span />
8 0
3 years ago
Read 2 more answers
How would you arrange the objects below from greatest to least volume?
ikadub [295]

Answer:

A balloon

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Explanation:

4 0
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Comment Both propane and benzene are hydrocarbons. As a rule,
kozerog [31]

The enthalpy change : -196.2 kJ/mol

<h3>Further explanation  </h3>

The change in enthalpy in the formation of 1 mole of the elements is called enthalpy of formation  

The enthalpy of formation measured in standard conditions (25 ° C, 1 atm) is called the standard enthalpy of formation (ΔHf °)  

(ΔH) can be positive (endothermic = requires heat) or negative (exothermic = releasing heat)  

The value of ° H ° can be calculated from the change in enthalpy of standard formation:  

∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)  

Reaction

2 H₂O₂(l)-→ 2 H₂O(l) + O₂(g)

∆H ° rxn = 2. ∆Hf ° H₂O - 2. ∆Hf °H₂O₂

\tt \Delta H_{rxn}=2.(-285.8)-2.(-187.8)\\\\\Delta H_{rxn}=-571.6+375.4=-196.2~kJ/mol\rightarrow \Delta Hf~O_2=0

5 0
3 years ago
2 KCIO3 - 2 KCl + 302;<br>Type of Reaction?<br><br>​
Ierofanga [76]

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6 0
3 years ago
How many pili are in a bacterial cell
Snowcat [4.5K]

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These are hollow, non-helical, filamentous appendages.

Hope it helps you

7 0
2 years ago
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