Hello!
The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.
We have the following data:
mo (initial mass) = 53.3 mg
m (final mass after time T) = ? (in mg)
x (number of periods elapsed) = ?
P (Half-life) = 10.0 minutes
T (Elapsed time for sample reduction) = 25.9 minutes
Let's find the number of periods elapsed (x), let us see:






Now, let's find the final mass (m) of this isotope after the elapsed time, let's see:




I Hope this helps, greetings ... DexteR! =)
Answer:
Convection.
Explanation:
Why? This transfer of heat energy away from the ground by the vertical movement of air is called "free convection" or "natural convection." A hot air balloon rises because warmer air is less dense than cool air. (plz brainlyest)
I think is 1 and a half km
Answer:
20.3 % NaCl
Explanation:
Given data:
Mass of solute = 45.09 g
Mass of solvent = 174.9 g
Mass percent of solution = ?
Solution:
Mass of solution = 45.09 g + 174.9 g
Mass of solution = 220 g
The solute in 220 g is 45.09 g
220 g = 2.22 × 45.09
In 100 g solution amount of solute:
45.09 g/2.22 = 20.3 g
Thus m/m% = 20.3 % NaCl
Answer:
55.52°
Explanation:
Concept tested: Sine rule of triangles
We need to know the sine rule
- According to sine rule, if the three sides of a triangle are a, b and c and the corresponding angles, A, B and C
- Then,

In this case;
- If we take, a = 5.7 units and A = 70°, and
b= 5 units, B = x°
- Using the sine rule we can find the value of x
Therefore;

Then;



Therefore, X = 55.52°
Therefore, the value of x in the triangle is 55.52°