Answer:
A = 349 g.
Explanation:
Hello there!
In this case, since the radioactive decay kinetic model is based on the first-order kinetics whose integrated rate law is:
We can firstly calculate the rate constant given the half-life as shown below:
Therefore, we can next plug in the rate constant, elapsed time and initial mass of the radioactive to obtain:
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Answer:
7.5 L
Explanation:
Using Charles' law, which is V1/T1=V2/T2, we can plug in these numbers to find the answer. The law states that volume is directly proportional to temperature. 3.0L/100K = x L / 250 K. Solve for x to get 7.5 L. Hope this helps.
Answer:
Explanation:
The first one is CrO. The Chromium has the same charge as the oxygen so mol numbers are dropped.
The Second one is CrO2 The two oxygens have a charge of 2(-2) = -4. To balance this, the Chromium must have a charge of +4 Cr(Iv)O2
The third one is can be set up like this
Cr + 3(-2) = 0
Cr - 6 = 0
Cr = 6
Therefore the formula is Cr(vi)O3
The last one is a bit tricky. Follow this carefully. There are 2 Crs and 3Os.
The formula looks like this
2Cr + 3(-2) = 0
2Cr - 6 = 0
2Cr = 6
Cr = 3
The formula is Cr(iii)2 O3
Answer:
decrease
Explanation:
Atomic radius
:
It is the distance from the center of nucleus to the outer most electronic shell.
Trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required
Answer:
Pressure
Explanation:
Basically when you are pressing something you are applying force over an area thus Pressure is force divided by area.
