89.1% Au
The molar mass of Au2O3 is 2(196.97) + 3(16.00) = 441.94 g/mol
The mass percent of Au is therefore 2(196.97) / 441.94, which is 393.94/441.94 = 0.891 —> 89.1%
Among the choices given, the best answer is the third option. Melting ice shows an increase in entropy. Entropy is the degree of disorderliness in a
system. Among the phases, solid has the most ordered structure which means it has the least entropy. The ice melting shows a phase change from solid to liquid. Liquid molecules are more disorganized than the solid thus there is an increase in entropy.
Answer:
The catalyzed reaction will take time of
.
Explanation:
According to the Arrhenius equation,

The expression used with catalyst and without catalyst is,


where,
= rate of reaction with catalyst
= rate of reaction without catalyst
= activation energy with catalyst = 59.0 kJ/mol = 59000 J/mol
= activation energy without catalyst = 184 kJ/mol = 184000 J/mol
R = gas constant
T = temperature = 
Now put all the given values in this formula, we get:

The reaction enhances by
when catalyst is present.
Time taken by reaction without catalyzed = 3900 years
Time taken by reaction with catalyzed = x

The catalyzed reaction will take time of
.
If the liquid is at or above its flash point, the flame spread rate is fast, and the entire pool is engulfed within seconds. ... As the liquid temperature decreases, flame radiation must both heat the liquid to the flash point temperature and supply the heat of vaporization.
Answer:
A) They all have 12 protons.
Explanation:
Magnesium has an atomic number of 12 which means it has 12 protons. All Magnesium atoms have 12 protons, the neutrons however may differ which produces things called isotopes where the atoms have same protons but neutrons change.
Keep in mind the atomic number is unique to each element, so 12 atomic number will always be Magnesium, 1 will always be Hydrogen and so on.....