A bridge must be made of metal or concrete or other materials that are strong enough to withstand the forces of the traffic passing over it. I doubt that the material could do that.
If the substance is a metal foam, it would make a rather hard cushion.
If the substance is too soft, it would make a cushion.
If the substance has the right combination of softness and elasticity so that it returns to its original shape when you get up, it might be a good material for a cushion.
Answer : The value of activation energy for this reaction is 108.318 kJ/mol
Explanation :
The Arrhenius equation is written as:

Taking logarithm on both the sides, we get:
............(1)
where,
k = rate constant = 
Ea = activation energy = ?
T = temperature = 435 K
R = gas constant = 8.314 J/K.mole
A = pre-exponential factor = 
Now we have to calculate the value of rate constant by putting the given values in equation 1, we get:


Therefore, the value of activation energy for this reaction is 108.318 kJ/mol
An acid can be defined as a proton donor.
The alpha particle is the helium nucleus.
The mass of helium nucleus (⁴₂He) is 4u.
The mass of radioactive atom decreases by 4u. Look at the reaction below:
²²³₈₈Ra ---> ⁴₂He + ²¹⁹₈₆Rn
<h3>Answer:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).
<h3>Solution:</h3>
According to Boyle's Law, " <em>The Volume of a given mass of gas at constant temperature is inversely proportional to the applied Pressure</em>". Mathematically, the initial and final states of gas are given as,
P₁ V₁ = P₂ V₂ ----------- (1)
Data Given;
P₁ = 500 mmHg
V₁ = 9.0 mL
P₂ = 750 mmHg
V₂ = ??
Solving equation 1 for V₂,
V₂ = P₁ V₁ / P₂
Putting values,
V₂ = (500 mmHg × 9.0 mL) ÷ 750 mmHg
V₂ = 6.0 mL
<h3>Result:</h3>
The New pressure (750 mmHg) is greater than the original pressure (500 mmHg) hence, the new volume (6.0 mL) is smaller than the original volume (9.0 mL).