Answer:
Histamine is a protein produced by <u>mast cells</u> in the body. It plays a very important role in the immune system of the body. Histamine is released in the body when <u>affected by an allergen</u>, e.g, pollen or animal dander. The immune system of the body will respond to such allergen by <u>making more mucus in the nose by releasing histamine</u>. There will be sneezing, itching, coughing and runny nose in response. This is a <u>basic defense of the body's immune system</u> to not enter any particle inside the body.
Gamma rays consist of pure energy. Beta particles consist of one electron that is released at high speeds from an unstable nucleus and an alpha particle is a helium nucleus.
We know that Gamma rays consist of pure energy because, during Gamma decay, the atomic and mass numbers remain unchanged. Therefore, only energy is emitted.
Gamma rays are weakly ionising, however, they are strongly penetrating and thick concrete or a few centimetres of aluminium is needed to stop them.
Answer:
J.J.Thomson discovered negatively charged particles by cathode ray tube experiment in the year 1897. The particles were name electrons.
Answer:
The specific heat capacity of the unknown metal is 0.223 
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
There is a direct proportional relationship between heat and temperature. The constant of proportionality depends on the substance that constitutes the body as on its mass, and is the product of the specific heat by the mass of the body. So, the equation that allows calculating heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, made up of a specific heat substance c and where ΔT is the temperature variation.
In this case, you know:
- Q= 418.6 J
- c= ?
- m= 75 g
- ΔT= 25 C
Replacing:
418.6 J= c* 75 g* 25 C
Solving:
c= 0.223
<u><em>The specific heat capacity of the unknown metal is 0.223 </em></u><u><em></em></u>
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Answer:
1.2 liters.
Explanation:
Focus on the 4th digit: that's the ones column. The 3rd digit is the decimal place, just be sure to round up.
