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Montano1993 [528]
3 years ago
13

Which astronomer spent 20 years plotting the positions of the planets?

Chemistry
1 answer:
devlian [24]3 years ago
3 0

Answer:

Tycho Brahe

Explanation:

Tycho Brahe spent 20 years in plotting the positions of the planets. He was among a group of astronomers who helped developing heliocentric model of the universe.

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Of the groups given, which are the least chemically reactive?
AfilCa [17]

Answer:

Group 8A

Explanation:

This is because the elements in Group 8A is stable, what I mean is this elements have the maximum number of electrons in there last orbit so they dont need to form any compund with any other element in the periodic table.

<em>HOPE</em><em> </em><em>THIS</em><em> </em><em>WILL</em><em> </em><em>HELP YOU</em><em /><em>❤️</em>

7 0
2 years ago
Table B: Enthalpy of Formation of Reactants and Products
Inessa [10]

The calculated enthalpy values are as follows:

  • Total enthalpy of reactants = -103.85 KJ/mol
  • Total enthalpy of products = -2057.68 KJ/mol
  • Enthalpy of reaction = -1953.83 kJ/mol

<h3>What is the enthalpy of the reaction?</h3>

The enthalpy of the reaction is determined as follows:

  • Enthalpy of reaction = Total enthalpy of products -Total enthalpy of reactants
  • Total enthalpy of reactants = (ΔHf of Reactant 1 x Coefficient) + (ΔHf of Reactant 2 x Coefficient)
  • Total enthalpy of products= (ΔHf of Product 1 x Coefficient) + (ΔHf of Product 2 x Coefficient)

Equation of reaction equation: C₃H₈ (g) + 5 O(g) → 4 H₂O(g) + 3CO₂(g)

Total enthalpy of reactants = (-103.85 * 1) + (0 * 5)

Total enthalpy of reactants = -103.85 + 0

Total enthalpy of reactants = -103.85 KJ/mol

Total enthalpy of products = (-393.51 * 4) +(-241.82 * 3)

Total enthalpy of products = (-1574.04) + (-483.64)

Total enthalpy of products = -2057.68 KJ/mol

Enthalpy of reaction =  -2057.68 KJ/mol -(-103.85 KJ/mol)

Enthalpy of reaction = -1953.83 kJ/mol

In conclusion, the enthalpy of the reaction is determined from the difference between the total enthalpy of products and reactants.

Learn more about enthalpy of reaction at: brainly.com/question/14047927

#SPJ1

5 0
1 year ago
Please help me <br> Vote you brainiest but please just help
Goryan [66]
Their average speed during the trip is 53 km/ hr approximately

Explanation: The family traveled 80 km/hr for an hour and then trabeled 40 km/ hr for 2 hours. So they traveled 80 km in one hour then 80 km in the next 2 hours. Total they traveled 160 km in 3 hours.
Average speed = distance traveled/ taken time
= 160/3 = 53.33
4 0
3 years ago
What will cause the particles of a solid to become arranged in a more random manner
Elanso [62]
The correct answer is D. melting the solid. 
6 0
3 years ago
Please help!!!!!!!!!!!!!!!!
STALIN [3.7K]
1. Dmitri created groups of 3
2. John Newlands arranged the elements
3. Antoine Lavoisier divided them into catagories
4. Johann used patterns

hope this helped :) 
3 0
3 years ago
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