<span>The immune system fights off infectious disease. This is the system which produces cells that fight off the common cold. This system is also very closely related to the lymphatic system. Some people have much stronger immune systems that others.</span>
"Chemical Energy" <span>in gasoline is transformed into mechanical energy and a motorcycle engine
Hope this helps!</span>
Answer:
<h2>500 J</h2>
Explanation:
The kinetic energy of an object can be found by using the formula
where
m is the mass
v is the velocity
From the question
m = 1.6 kg
v = 25 m/s
We have
We have the final answer as
<h3>500 J </h3>
Hope this helps you
Answer:
d. Radon-222
Explanation:
²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He
Alpha particle is a helium nucleus with mass number 4 and atomic number 2. According to the law of conversation of mass, the sum of the mass number and atomic number must be equal on both side of the reaction.
Since the mass number of Ra is 226 and that of He is 4. The mass number of the unknown element must be 226 - 4 = 222.
Since the atomic number of Ra is 88 and that of He is 2. The atomic number of the unknown element must be 88 - 2 = 86.
Now looking in the periodic table Radon is the only element with atomic number 86.
