There are a few ways to slow down a chemical reaction:
Provide less heat
; adding heat increases particle movement, speeding up a reaction.
Less surface area
: a larger surface area often also speeds up the reaction.
Less quantity of the element
<span>Fry's Reagent a chemical used on metals such as firearms, it corrodes them and allows you to see the etching that could have been scratched off by the criminal, such as the serial number of the gun. It is </span><span>a chemical that can restore a serial number that has been removed from a gun by dissolving the area that has been flattened when the number was stamped on.</span>
It's would turn pink in a basic solution suck as water.
Answer:
138 mg
Explanation:
A company is testing drinking water and wants to ensure that Ca content is below 155 ppm (= 155 mg/kg), that is, <em>155 milligrams of calcium per kilogram of drinking water</em>. We need to find the maximum amount of calcium in 890 g of drinking water.
Step 1: Convert the mass of drinking water to kilograms.
We will use the relation 1 kg = 1000 g.

Step 2: Calculate the maximum amount of calcium in 0.890 kg of drinking water
