Given, half life of a certain radioactive element = 800 years.
Amount of substance remaining at time t = 12.5%
Lets consider the initial amount of the radioactive substance = 100%
Using the half life equation:
A = A₀(1/2)^t/t₁/₂
where A₀ is the amount of radioactive substance at time zero and A is the amount of radioactive substance at time t, and t₁/₂ is the half-life of the radioactive substance.
Plugging the given data into the half life equation we have,
12.5 = 100 . (1/2)^t/800
12.5/100 = (1/2)^t/800
0.125 = (0.5)^t/800
(0.5)^3 = (0.5)^t/800
3 = t/800
t = 2400 years
Thus the object is 2400 years old.
Answer: B. The element called tin is a metal with the chemical symbol Sn.
Explanation:
A is incorrect because Ni is Nickel, not Niobium.
C is incorrect because Carbon is a nonmetal and its symbol is C, not Cr.
D is incorrect because Copper's symbol is Cu, not Ce.
E is incorrect because As is the symbol for Arsenic, not Astatine.
<h3>your query : </h3>
Which statement about photosynthesis is FALSE?
Answer:
b. Oxygen is needed as a reactant to produce
glucose is the incorrect statement here
Explanation:
plants uses simple raw materials to prepare their food , which includes water ( H2O ) and Carbon dioxide ( CO2 ).
and traps sunlight by Green pigments known as chlorophyll and stores these energy in bonds of glucose molecules
so ,
after this reaction glucose and oxygen is formed as products
● hence we conclude that Oxygen is not needed as a reactant to produce glucose , oxygen is the bi product formed during photosynthesis.
From what is given, double replacement is what it is
Photosynthesis is where carbon dioxide and water through light energy is converted in glucose and other organic compounds.
