The matter that has the same composition and properties throughout is called pure chemical substance. So the answer is substance.
Answer:
C. Adding a catalyst
Explanation:
Because the catalyst increases the rate of chemical reaction
1. 2CaS + 2H2O --> Ca(HS)^2 + Ca(OH)^2
2. Au^2S^3 + 3H2 --> 2Au + 3H2S
Answer:
24 molecules of H20
Explanation:
Photosynthesis:
It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.
Carbon dioxide + water + energy → glucose + oxygen
water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture by chloroplast.
Chemical equation:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen.
consider 1 mole contain 1 molecule.
So in order to produced 4 molecules of sugar number of molecules of water carbon dioxide needed are,
6 × 4 = 24 molecules
24 molecules of water and 24 molecules of carbon dioxide needed.
The half life of an isotope is the amount of time it will take for the given isotope to decay till the point where it reaches half of what amount you had started with.
If the half life of Ra-229 is 4 minutes then every 4 minutes the sample is reduced to half of what you had before
4 minutes.) 50/2 Ra-229 --> 25g Ra-229
8 minutes.) 25/2 Ra-229 --> 12.5 Ra-229
12 minutes.) 12.5/2 Ra-229 --> 6.25 Ra-229 remaining
<em>I beleive this is the correct answer</em>
