Given:
Half life(t^ 1/2) :30 years
A0( initial mass of the substance): 200 mg.
Now we know that
A= A0/ [2 ^ (t/√t)]
Where A is the mass that remains after t years.
A0 is the initial mass
t is the time
t^1/2 is the half life
Substituting the given values in the above equation we get
A= [200/ 2^(t/30) ] mg
Thus the mass remaining after t years is [200/ 2^(t/30) ] mg
The answer is 0.59 M.
Molar mass (Mr) of MgCl₂ is the sum of the molar masses of its elements.
So, from the periodic table:
Mr(Mg) = 24.3 g/l
Mr(Cl) = 35.45 g/l
Mr(MgCl₂) = Mr(Mg) + 2Mr(Cl) = 24.3 + 2 · 35.45 = 24.3 + 70.9 = 95.2 g/l
So, 1 mol has 95.2 g/l.
Our solution contains 55.8g in 1 l of solution, which is 55.8 g/l
Now, we need to make a proportion:
1 mole has 95.2 g/l, how much moles will have 55.8 g/l:
1 M : 95.2 g/l = x : 55.8 g/l
x = 1 M · 55.8 g/l ÷ 95.2 g/l ≈ 0.59 M
Explanation:
When the forces acting on an object are balanced , there is no change in the object's motion.
A force acting on a resting object can cause the object to move.
On Earth, gravity pulls all objects toward the ground.
When a force acts in the opposite direction of another force, the forces counteract each other.
More than one force acting on a falling object can reduce its downward acceleration
Air resistance is caused by molecules of air pushing against a moving object
Rubidium or strontium have larger a larger atomic radius since the further left on the periodic table you go, the larger the sizes of the atoms are. This trend can be explained through effective nuclear charge which explains how the further left and down you go, the less the atoms nucleus is able to pull in the electrons around it.<span />
The number of protons found in the nucleus equals the number of electrons that surround it, giving the atom a neutral charge (neutrons have zero charge). Most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen.Hoped this helped
