Answer:
The temperature will decrease (get colder).
Explanation:
Enthalpy changes are heat changes accompanying physical and chemical changes. The enthalpy change is the difference between the sum of the heat contents of products and the sum of heat contents of reactants.
- For an endothermic change, heat is absorbed for the reaction.
- The surrounding becomes colder at the end of the reaction and so is the reaction itself.
- The right choice is that the temperature will decrease.
Answer:
Explanation:
Of the 4 numbers given, the answer is 1 or A
If you take the absolute value of abs(1 - 1.04) you get 0.04.
(2 - 1.04) = 0.96
1.25 - 1.04 = .21
1.5 - 1.04 = 0.46
The last three are all larger than 0.04
Note: absolute value means the positive difference between 2 numbers (even though it is negative). If it is negative, absolute value makes it positive.
Answer:
K_a = 8,111 J
Explanation:
This is a collision exercise, let's define the system as formed by the two particles A and B, in this way the forces during the collision are internal and the moment is conserved
initial instant. Just before dropping the particles
p₀ = 0
final moment
p_f = m_a v_a + m_b v_b
p₀ = p_f
0 = m_a v_a + m_b v_b
tells us that
m_a = 8 m_b
0 = 8 m_b v_a + m_b v_b
v_b = - 8 v_a (1)
indicate that the transfer is complete, therefore the kinematic energy is conserved
starting point
Em₀ = K₀ = 73 J
final point. After separating the body
Em_f = K_f = ½ m_a v_a² + ½ m_b v_b²
K₀ = K_f
73 = ½ m_a (v_a² + v_b² / 8)
we substitute equation 1
73 = ½ m_a (v_a² + 8² v_a² / 8)
73 = ½ m_a (9 v_a²)
73/9 = ½ m_a (v_a²) = K_a
K_a = 8,111 J
Which best describes the transition from gas to liquid?
gas is @ higher energy state than liq. so the transition must remove energy. so ans is a. Energy must be removed because particles in liquid move more slowly.
Mass extinction occur from natural disasters, such as a n asteroid hitting earth or a volcano errupting and spread ash everywhere.
It makes sense to measure geologic time between mass extinctions because after each mass extinction, there is almost no life left and the few left have to repopulate, which may lead way to new mutations and new varieties of plants and animals.
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