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omeli [17]
3 years ago
7

Rebecca is playing a video game that involves planting and cutting down trees. She moves up an energy level for each tree she pl

ants, and she moves down a level for each tree she cuts. If Rebecca reaches energy level 10, she will earn bonus points. Rebecca is currently at energy level 4. The results of her next 3 turns are: Turn 1: 6 trees cut Turn 2: 8 trees planted Turn 3: 1 tree cut
USING ONLY ADDITION, write an expression that represents Rebecca's score after these three turns. (Remember that she starts at an energy level of 4.)
Chemistry
1 answer:
kipiarov [429]3 years ago
8 0

Answer:

she ends at level 5 after her 3 turns

Explanation:

Rebecca starts at level 4 if she cuts down 6 trees for her next turn she loses 6 levels we can rewrite this as -6 so 4 + (-6) = -2 her next turn is planting 8 trees so she goes up 8 levels -2 + 8 = 6 her last turn she cuts down one tree

6 + (-1) = 5

altogether 4 + (-6) + 8 + (-1) = 5

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How are heat work and internal energy related?
julsineya [31]

The change in internal energy that accompanies the transfer of heat (q) or work (w), into or out of a system can be calculated using the following equation: Note the value of heat and work as they are transferred into or out of a system.

5 0
4 years ago
Dissolving 4.02 g of CaCl2 in enough water to make 349 mL of solution causes the temperature of the solution to increase by 3.91
gregori [183]

Answer:

ΔH per mole of CaCl2 is 160.3 kJ

Explanation:

<u>Step 1: </u>The balanced equation

CaCl2 (aq)→  Ca2+  +  2Cl-(aq)

<u>Step 2:</u> Data given

Molar mass of CaCl2 =110.98 g/mole

mass of CaCl2 = 4.02 grams

volume of the solution = 349 mL = 0.349 L

Temperature increases with 3.91 °C

Specific heat of the solution = specific hea of water = 4.18 J/°C*g

Density solution = density water = 1g/cm³

<u>Step 3:</u> Calculate moles of CaCl2

Numer of moles of CaCl2 = mass of CaCl2 / Molar mass of CaCl2

Number of moles = 4.02 grams /110.98 g/mole= 0.036 moles

<u>Step 4</u> = Calculate amount of heat added

Q = m*c*ΔT

with m = the mass 349 grams + 4.02 grams = 353.02 grams

c = 4.18 J/°C*g

ΔT = 3.91 °C

Q = 353.02*4.18*3.91 = 5769.69 J

Step 5: Calculate ΔH per mole

5769.69 J /0.036 moles = 160269.1 J = 160.3 kJ

ΔH per mole of CaCl2 is 160.3 kJ

6 0
3 years ago
50 points!!!<br> Please help me
oee [108]
30. mixture of compounds
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32. element
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34. compound
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5 0
3 years ago
My question is on the image
Rainbow [258]

Answer:

Top left: RR Top right: Rr Bottom left: Rr Bottom right: rr

Explanation:

if both parents are heterozygous then the table will always look like this. the chances of the offspring being heterozygous are 50%. the offspring has a 25% chance of having two recessive traits and a 25% chance of having two dominant traits.

4 0
3 years ago
In the picture below, the green spheres represent particles of solute that have been added to water. Bonds between the solute pa
ololo11 [35]

Answer:

As they absorb energy, they are broken.

Explanation:

Solutes dissolve when they interact with water. This is because, the attraction of solute particles with each other weakens and become replaced by solute-solvent interaction. As the water surrounds the solute, the solute is now said to be hydrated.

Energy is required to break solute-solute bonds. This energy absorbed in breaking solute-solute bonds is compensated for by the energy liberated when solute particles are hydrated.

If energy required to break solute-solute interaction is less than the energy liberated when solute particles are hydrated, the substance will dissolve in water.

Hence, as a substance dissolve in water, energy is absorbed when solute-solute interactions are broken.

8 0
3 years ago
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