Explanation:
Initial mass of the isotope 90-Sr in baby= 1.00 μg
Formula used :
where,
= initial mass of isotope
N = mass of the parent isotope left after the time, (t)
= half life of the isotope = 28.1 years
= rate constant
a) Time taken by the sample, t = 18 years
0.6415 μg will remain after 18 years.
b) Time taken by the sample, t = 70 years
0.1779 μg will remain after 70 years.
Use the equation P=VI.
P=power (in this case 10 kilowatts or 10000 watts)
V=voltage (in this case unknown)
I=current (in this case 15.8 amps)
rewrite the equation to be V=P/I
V=(10000 watts)/(15.8 amps)
V=632.9 volts
(I think the equation requires the units for power to be watts so you need to convert kilowatts into watts)
Gesso is a white paint blend that comprises pigment, chalk and gypsum. It is a medium utilised for surface preparation and as a primer for a painting.
<h3>What are the uses of gesso?</h3>
Gesso is widely utilized for preparing surfaces and as primers by painters. They were used by painters and artists earlier to make canvas, boards for painting purposes.
It was first formulated by chalk powder dust and pigment derived from the animal skin. They are widely used because of their adhering properties.
The use of the gesso makes the paint adhere to the canvas and the board surfaces and also, makes the surface textured.
Therefore, option b. it is used for preparing the surface is correct.
Learn more about gesso here:
brainly.com/question/1191408
Answer:
The answer to your question is 12
Explanation:
Data
Number of electrons in Phosphorus 3+ ion
Process
1.- The sign of the number after the name indicates if the element has lost or gained electrons.
If the sign is positive the element has lost electrons
If the sign is negative the element has gained electrons.
2.- Phosphorus atomic number is 15, then the number of electrons in Phosphorus 3+ will be 12, in this example, Phosphorus lost 3 electrons.
