B) is an example of a Double Displacement Reaction:
<span>Ba Cl2 + K2 CO3 ---> Ba CO3 + 2K Cl
</span>A B C D A D B C
<span>A 50-gram sample with a half-life of 12 days will have a remaining mass of 25 grams after its 12-day half-life.
Every cycle of a half-life, the sample will lose half of its mass, so if the half-life, itself, is 12 days and the time period passing is 12 days, one half-life has passed and the material will be halved.</span>
Answer: 6.25 mol
Explanation:
From the reaction that produces water from its elements (shown in the image), we know that for every mole of oxygen gas consumed, 2 moles of water are produced.
This means that 12.5/2=<u>6.25 mol</u> of oxygen gas is needed.
The horizontal rows in the periodic table are periods, while the vertical rows are called groups. The elements moving from left to right in "periods" have increasing atomic numbers.
I think u should divide the number by 2 i think.