Answer:
A chemical change because a temperature change occurred, the solid disappeared and a gas was produces
Explanation:
Magnesium reacts with hydrochloric acid releasing energy, and leading to the formation of magnesium chloride and hydrogen gas. This is represented by the equation below:
Mg₍s₎ + 2HCl₍aq)⇒ MgCl₂₍aq₎ + H₂₍g₎
<span>The pH of a vinegar solution is 4.15. To find the H+ concentration of the solution use the following equation -log(H+)=pH.
Insert the pH into the equation to get, -log(H+) = 4.15
Rearrange the equation to get, 10^(-4.15) = H+
Finally, you can solve for H+.
The hydrogen ion concentration of the vinegar solution is .0000708 M.</span>
Answer:
Here is one way: Add water to the mixture. Only the sugar dissolves. This is a physical change.
Explanation:
The sugar would dissolve in water. You could then pour off the solution and wash the remaining sand with a bit more water. Heat the water to evaporate it from the sugar, and the two are separated.
Answer:
Electrons have an electric charge of -1.60 × 10-19 C
Explanation:
Neutrinos and Neutrons have 0 e charge.
Protons have an electric charge of 1.60 × 10-19 C
Historically, electrons were assigned a negative charge
After 25 days, it remains radon 5.9x10^5 atoms.
Half-life is the time required for a quantity (in this example number of radioactive radon) to reduce to half its initial value.
N(Ra) = 5.7×10^7; initial number of radon atoms
t1/2(Ra) = 3.8 days; the half-life of the radon is 3.8 days
n = 25 days / 3.8 days
n = 6.58; number of half-lifes of radon
N1(Ra) = N(Ra) x (1/2)^n
N1(Ra) = 5.7×10^7 x (1/2)^6.58
N1(Ra) = 5.9x10^5; number of radon atoms after 25 days
The half-life is independent of initial concentration (size of the sample).
More about half-life: brainly.com/question/1160651
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