Answer:
The mass of Uranium present in a 1.2mg sample is 
Explanation:
The ration between Uranium mass and total sample mass is:
For a sample of mass 1.2 mg, the amount of uranium is:

Compounds are elements that are chemically combined, like water for example (it’s both hydrogen and oxygen.)
Answer: The average speed is 27,24 mph (exactly 1008/37 mph)
Explanation:
This is solved using a three rule: We know the speeds and the distances, what we can obtain from it is the time used. It is done like this:
1h--->18mi
X ---->20 mi, then X=20mi*1h/18mi= 10/9 h=1,111 h
1h--->56mi
X ---->20 mi, then X=20mi*1h/56mi= 5/14 h=0,35714 h
Then the average speed is calculated by taking into account that it was traveled 40mi and the time used was 185/126 h=1,468 h and since speed is distance over time we get the answer. Average speed= 40mi/(185/126 h)=1008/37 mph=27,24 mph.
Waves transmit energy without transmitting matter, This means that we can move energy or information from one place to another without moving any substance from one place to another.
<u>Answer</u>
1) A. 96 Candelas
2) A. Both of these types of lenses have the ability to produce upright images.
3) C. 5 meters
<u>Explanation</u>
Q1
The formula for calculation the luminous intensity is;
Luminous intensity = illuminance × square radius
Lv = Ev × r²
= 6 × 4²
= 6 × 16
= 96 Candelabra
Q2
For converging lenses, an upright image is formed when the object is between the lens and the principal focus while a diverging lens always forms and upright image.
A. Both of these types of lenses have the ability to produce upright images.
Q3
Luminous intensity = illuminance × square radius
square radius = Luminous intensity/ illuminance
r² = 100/4
= 25
r = √25
= 5 m