Answer:
<h3>Step 1: </h3>
To relate the volume and molarity of a solution at two different concentrations, the expression used is :
M₁V₁ = M₂V₂
<h3>
step 2:</h3>
(2M) V₁ = (0.15M)(250ML)
V₁ = 18.75
step 3:
<h2>Pls, branliest! :)</h2>
Answer:
Explanation:
Isotopes are atoms of elements that have the same atomic number but different mass number hence ISOTOPY. Radioactive Isotopes on the other hand are unstable as they either undergo Alpha decay, beta decay or gamma decay compared to stable isotopes.
Radioactive elements decay at varyinf rates as such the rate of radioactive decay is used in the characterization of radioactive element and mostly expressed in terms of the half life of the radioactive elements.
Half life is the time taken for half of the total atoms of an elements to decay into half of its initial sizes. for example, the half life of radium-226 is 1622 years, it implies that if we have 1000000 radium atoms at the beginning, then at the end of 1622years, 500000 would have disintegrated. These phenomenon can never be experienced by stable isotopes as such they can not be used in carbon dating techniques. reason why uranium-238 is mostly and commonly used in the earth crust to estimate the ages of rocks because it has a half life of 4.5 x 10^9 years.
And also, the radioactive isotopes of most common light element are short, they have very short half life (few days or weeks) and they decay rapidly to vanshing point, as such, they are not found in nature to any reasonable extent.
Electrons are added to the same principal energy level.
Explanation:
When we increase the temperature of a substance then there will occur an increase in the kinetic energy of its molecules.
Also, K.E = 
So, kinetic energy is directly proportional to the temperature.
Hence, when temperature and pressure are kept the same for both oxygen and hydrogen gas then values of their kinetic energy will be the same irrespective of their masses.
Thus, we can conclude that kinetic energy of oxygen molecule is the same as compared to hydrogen molecule.
