Answer:
Uranium-238 or lead-206 are most often used to date rocks. ... Carbon-14's half-life is much too long to use for dating rocks. C) The half life of carbon-14 is about 5700 years and is too short date rocks. D) Carbon-14 is only found in living things; it can only be used to date remains
Explanation:
hope this helps
Explanation:
Below is an attachment containing the solution to the question.
Answer:
Explanation:
You can't award 20 points once you have awarded 5.
One
2K + Cl2 ==> 2KCl
It's True
There are 2 Ks and Cl2 has 2 atoms making up on the left.
On the right, 1 molecule of KCl has 1 Potassium and 1 Cl. But there are 2 molecules so between the two of them, there's 2 Potassiums and 2 Cl
Two
The reactant side is the Left side. Cl2 means there are 2 Cl atoms making Cl2. Answer B
Three
False: There are 2 but read below.
I really don't know how to answer that. It's not qualified enough. There are a total of 2 Chlorines on the right hand side when there are 2 molecules. I think you are intended to answer False, but don't be surprised if you get it wrong.
Answer:
- <u><em>Option C) Fr (francium)</em></u>
Explanation:
<em>Fluorine (F) </em>is not a metal; thus, the last option is discarded quickly.
The<em> most reactive metals</em> are the alkali metals, group 1 of the periodic table, because they have just one valence electron, which they can release more easily than other metals which have more valence electrons.
<em>Lithium(Li)</em> and <em>francium (Fr)</em> are alkali metals, while <em>aluminum (Al)</em> belongs to group 13, which means that it has 3 valence electrons.
Thus, aluminum is out of race too.
Lithium is in the second period (row 2 of the periodic table) while francium is in the last period (row 7).
The reactivity of metals in a group increases from top to bottom, because the valence electrons are shielded by many electrons (which are in the orbitals of less energy and closer to the nucleus of the atom), meaning that the valence eletrons can be released more easily.
Hence, the most reactive metal from the list is Fr (francium), option C).
First write out the balanced equation. 3Cu+2Ag(NO3)3=2Ag+3Cu(NO3)2
Then convert copper from grams to moles
15 g*1 mol cu/63.54 g= 15/63.54 mol cu
Then use the mole ratio to convert Moles Cu to Moles Ag
15/63.54 moles Cu* 2 moles Ag/3 moles Cu
The final awnser is (15*2)/(63.54*3) moles Ag =0.157 moles Ag. If the question wants the answer in grams, convert from moles Ag to grams Ag.
0.157 moles Ag*107.87 g Ag/ mol Ag=16.98 g Ag