1. The

nikdorinn [45]

7. A conclusion is an educated guess,
or, prediction, about what will happen after the experiment.

8. In observation we use all five senses to gather information.

9. In result we analyze and summarize and ask if the hypothesis was correct.

10. Something that changes or varies in an experiment is called variable.

Ans:
Conclusion
Observation
Results
Variable

3 0

3 years ago

A male construction worker regularly consumes 18 000 kJ of energy per day. Suggest the effects this could have on his health.

Romashka [77]

Answer:

It could lead to Fatigue

Low energy.

Headaches.

Aches, pains, and tense muscles.

Chest pain and rapid heartbeat.

Explanation:

8 0

3 years ago

Please help. Thank you:)

bearhunter [10]

These are guesses because there is no word bank or anything

A. Water
B. Housing
C. Plants
D. Animals
E. Warmth

5 0

3 years ago

which statement describes the way in which energy moves between a system of reacting substances and surroundings

V125BC [204]

The complete question is as follows: Which statement describes the way in which energy moves between a system reacting substances in the surroundings.

A) molecule Collisions transfer thermal energy between the system and its surroundings

B) The thermal energy of the system and it’s surroundings increase

C) The potential energy of the system and it’s surroundings increases

D) molecular collisions create energy that is then released into the surroundings

Answer: The statement, molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

Explanation:

When there will occur an increase in kinetic energy of molecules then there will occur more number of collisions.

When kinetic energy between these molecules tends to decrease then they will release heat energy into their surroundings.

As a result, it means that molecule collisions transfer thermal energy between the system and its surroundings.

Thus, we can conclude that the statement molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

8 0

3 years ago

How much heat energy is required to convert 48.3 g of solid ethanol at -114.5 degree C to gasesous ethanol at 135.3 degree C? Th

OLEGan [10]

Answer:

7.21 × 10⁴ J

Explanation:

Ethanol is solid below -114.5°c, liquid between -114.5°C and 78.4°C, and gaseous above 78.4°C.

<em>How much heat energy is required to convert 48.3 g of solid ethanol at -114.5°C to gaseous ethanol at 135.3 °C?</em>

<em />

We need to calculate the heat required in different stages and then add them.

The moles of ethanol are:

$48.3g.\frac{1mol}{46.07g} =1.05mol$

Solid-liquid transition

Q₁ = ΔHfus . n = (4.60 kJ/mol) . 1.05 mol = 4.83 kJ = 4.83 × 10³ J

where,

ΔHfus: molar heat of fusion

n: moles

Liquid: from -114.5°C to 78.4°C

Q₂ = c(l) . m . ΔT = (2.45 J/g.°C) . 48.3g . [78.4°C-(-114.5°C)] = 2.28 × 10⁴ J

where,

c(l): specific heat capacity of the liquid

ΔT: change in the temperature

Liquid-gas transition

Q₃ = ΔHvap . n = (38.56 kJ/mol) . 1.05 mol = 40.5 kJ = 40.5 × 10³ J

where,

ΔHvap: molar heat of vaporization

Gas: from 78.4°C to 135.3°C

Q₄ = c(g) . m . ΔT = (1.43 J/g.°C) . 48.3g . (135.3°C-78.4°C) = 3.93 × 10³ J

where

c(g): specific heat capacity of the gas

Total heat required

Q₁ + Q₂ + Q₃ + Q₄ = 4.83 × 10³ J + 2.28 × 10⁴ J + 40.5 × 10³ J + 3.93 × 10³ J = 7.21 × 10⁴ J

3 0

3 years ago