Answer: This means to find the number of neutrons you subtract the number of protons from the mass number.
Answer:In the chemical formula Al2(SO4)3, the Al2 means there two aluminium (atoms or ions). The SO4 is a sulfate ion and (SO4)3 means there are 3 sulfate ions. The number 3 before Al2(SO4)3 means there are three times the number of atoms and ions of the chemical formula.
i believe the answer is, b. heat energy is continuously added at each step. As energy is added, the molecular motion/kinetic energy increases, and matter changes state. In the last state, plasma, enough energy has been added to cause the atoms to disassociate into ions.
hope this is right! :33
<span>Following is the match the mineral categories to their best descriptions:
a) </span>sulfide mineral: <span>Contain sulfur plus a metallic element
b) </span>sulfate mineral: <span>Compounds that have a sulfur atom surrounded by four oxygen atoms
c) </span>halide minerals: Contain elements like fluorine, bromine, iodine, or chlorine combined with metals. S<span>table salt is an example of this type of mineral
</span>d) carbonate mineral: Compounds made up of a carbon atom that is bordered by three oxygen atoms.
Answer:
1.135 M.
Explanation:
- For the reaction: <em>2HI → H₂ + I₂,</em>
The reaction is a second order reaction of HI,so the rate law of the reaction is: Rate = k[HI]².
- To solve this problem, we can use the integral law of second-order reactions:
<em>1/[A] = kt + 1/[A₀],</em>
where, k is the reate constant of the reaction (k = 1.57 x 10⁻⁵ M⁻¹s⁻¹),
t is the time of the reaction (t = 8 hours x 60 x 60 = 28800 s),
[A₀] is the initial concentration of HI ([A₀] = ?? M).
[A] is the remaining concentration of HI after hours ([A₀] = 0.75 M).
∵ 1/[A] = kt + 1/[A₀],
∴ 1/[A₀] = 1/[A] - kt
∴ 1/[A₀] = [1/(0.75 M)] - (1.57 x 10⁻⁵ M⁻¹s⁻¹)(28800 s) = 1.333 M⁻¹ - 0.4522 M⁻¹ = 0.8808 M⁻¹.
∴ [A₀] = 1/(0.0.8808 M⁻¹) = 1.135 M.
<em>So, the concentration of HI 8 hours earlier = 1.135 M.</em>
