He was testing an acid. So your answer will be C.
Hope this helps!
In the sun, two hydrogen nuclides react together to make an atom of helium. the process releases energy. This is nuclear fusion reaction. The Sun uses this reaction to release energy and heat.<span> Hydrogen nuclei fuse together to form helium nuclei and release energy. The formula that describes this reaction is the following: 1/1H+1/1H->3/2He</span>
The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
where A₀ is the initial amount, A is the amount after time t, t₁/₂ is the half file
The fraction of thorium-232 that remains in the rock after 2.8 billions years is,
A/A₀ = (1/2) ^ (2.8 x 10⁹/ 1.405 × 10¹⁰) = 0.871
Therefore, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
*Chemical: Burning of paper and log of wood. - Digestion of food. - Boiling an egg. - Chemical battery usage. - Electroplating a metal. - Baking a cake. - Milk going sour.
*Physical: An ice cube melting into water in your drink. - Freezing water to make ice cubes. - Boiling water evaporating. - Hot shower water turning to steam. - Steam from the shower condensing on a mirror.
