Answer:
a quantitative observation implies that the subject can be measured by quantity, aka amount or in numbers.
Ex 1: adding one gram of salt to one gram of sugar makes two grams of seasoning. in this example, there are individual quantities (1 gram of each) and total quantity (2 grams). this only changes if the substances have a chemical reaction, such as one of them destroying the other, then the weight would change.
Ex 2: a more simple example is the weight of something. putting the substance on a scale (one specifically for whatever you are measuring, whether it be liquid or solid) is the best way to determine its quantity.
Answer:
+1
Explanation:
A Potassium atom is represented with the sign "K" in chemistry and have atomic number 19.
The charge of electrons causes a matter to experience a force and it can be positive or negative.
In Potassium atom, the electric charge is +1 to enter a stable electron configuration as there is only one valence electron in the outermost shell of potassium atom. As potassium atom will lose electron it will become positively charged.
Hence, the correct answer is "+1".
Answer:
In physics, action is an attribute of the dynamics of a physical system from which the equations of motion of the system can be derived through the principle of stationary action. ... Action has dimensions of energy⋅time or momentum⋅length, and its SI unit is joule-second.
Explanation:
hope it helps
Answer:
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Explanation:
A <em>first order reaction</em> follows the law:
![rate=k[A]](https://tex.z-dn.net/?f=rate%3Dk%5BA%5D)
, where [A] is the concentraion of the reactant A.
Equivalently:
![\dfrac{d[A]}{dt}=-k[A]](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BA%5D%7D%7Bdt%7D%3D-k%5BA%5D)
Integrating:
![\dfrac{d[A]}{[A]}=-kdt](https://tex.z-dn.net/?f=%5Cdfrac%7Bd%5BA%5D%7D%7B%5BA%5D%7D%3D-kdt)
![\ln \dfrac{[A]}{[A_o]}=-kt](https://tex.z-dn.net/?f=%5Cln%20%5Cdfrac%7B%5BA%5D%7D%7B%5BA_o%5D%7D%3D-kt)
Half-life means [A]/[A₀] = 1/2, t = t½:
That means that the half-life is constant.
The slope of the plot of ln [N₂O₅] is -k. Then k is equal to 6.40 × 10⁻⁴ min⁻¹.
Thus, you can calculate t½:
t½ = ln(2) / 6.40 × 10⁻⁴ min⁻¹
t½ = 1,083 min.
Rounding to 3 significant figures, that is 1,080 min.
