Answer:
Potassium-40 (40K) is a radioactive isotope of potassium which has a long half-life of 1.251×109 years. It makes up 0.012% (120 ppm) of the total amount of potassium found in nature.
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Potassium-40.
General
Natural abundance 0.0117(1)%
Half-life 1.251(3)×109 y
Parent isotopes Primordial
Decay products 40Ca (β−) 40Ar (EC, γ; β+)
Answer: A. the transfer of heat by currents
Explanation: There are three modes of heat transfer:
1) Conduction: This type of heat transfer happens when there is direct contact between the two object. Example: heating a pan on stove.
2) Convection: This type of heat transfer happens when there is a movement of fluid (liquid or gas) due to the movement of hot layers to the top and cold layers to the bottom which leads to convection currents. Example: Heating of swimming pool.
3) Radiation: This type of heat transfer happens when there is direct transfer of energy through space. Example: Heating of earth's surface.
B. The transmission of heat across matter is conduction.
C. The electromagnetic radiation from the surface of an object which is due to the object's temperature is radiation.
D. The transmission of heat across empty space is radiation.
Answer:
Explanation:
Hello, since the Gibbs' phase rule states the following equation:
Whereas C is the number of components and P the present phases, you answers are:
1. F=1-2+2=1.
2. F=2-2+2=2.
3. F=2-2+2=2.
Best regards.
Answer:(1) 6 sodium ions
(2)The movement of iodide ions occurs in the same direction as the sodium ions.
Explanation: Sodium-iodide symporter actively transports 2 sodium ions together with one iodide ions across the basement membrane into the thyroid follicular cells.(therefore for production of a single molecule of T3 3×2=6 sodium ions)This system utilises the concentration of sodium ions so that iodide ions can move against its concentration gradient.
Answer:
Ⓓ The process follows the law of conservation of mass and energy is found in the product
Explanation:
This question depicts PHOTOSYNTHESIS, which is the process employed by green plants to manufacture their food in form of sugars (glucose). The general equation, which was given in the question is as follows:
6CO2 + 6H2O + energy → C6H12O6 + 6O2
This chemical reaction follows the LAW OF CONSERVATION OF MASS, which states that the amount of matter in reactant must equate that of the product. In this case, each element contains the same number of atoms in both reactant side and product side.
Also, energy is contained in the product but stored in the chemical bonds of the glucose molecule formed.
