Answer:
After 5 second 25% C-15 will remain.
Explanation:
Given data:
Half life of C-15 = 2.5 sec
Original amount = 100%
Sample remain after 5 sec = ?
Solution:
Number of half lives = T elapsed / half life
Number of half lives = 5 sec / 2.5 sec
Number of half lives = 2
At time zero = 100%
At first half life = 100%/2 = 50%
At second half life = 50%/2 = 25%
Thus after 5 second 25% C-15 will remain.
3.4 x10^3 best answer to the question
<span>Xenon has 8 valence electrons, each hydrogen atom has 1, therefore you have 8+4=12 valence electrons. 8 electrons are used to make 4 bonds between the Xe atom and the 4 hydrogen atoms. That leaves 12-8=4 left over electrons, which will occur in two lone pairs of electrons on the center xenon atom. There are 4 bonding pairs and two lone pairs of electrons and they will be arranged in an octahedral arrangement around the center atom, with the lone pairs across the molecule (180 degrees from each other). The resulting molecular structure will be square planar.</span><span>
8+4=12 valence electrons. 8 electrons are used to make 4 bonds between the Xe atom and the 4 hydrogen atoms. That leaves 12-8=4 left over electrons, which will occur in two lone pairs of electrons on the center xenon atom. There are 4 bonding pairs and two lone pairs of electrons and they will be arranged in an octahedral arrangement around the center atom, with the lone pairs across the molecule . The resulting structure is square planar.</span>
Before you can identify how much you need, first you need to
solve and write the equation.
You need to know first that you need to convert grams of ZnO --> moles of ZnO
= 358.5 g ZnO x 1 mol ZnO / 81.39g ZnO
Solve and it will give you = 4.40 mol of ZnO
Next, multiply the answer above to 1 mol O2 / 2 mol ZnO
It will give you the answer of 2.20 mol of O2
Multiply the answer above to the molar mass. This will give
you the answer of what you’re looking for.
Molar mass: 32
= 2.20 mol O2 x 32g O2 / 1 mol O2
= 70.4g O2
The grams of O2 that are required to produce 385.5 grams of
zno is: 70.4 g O2
