Chemical change because it cannot be reversed
Answer:
9 days, or 3 half-lives
Explanation:
5.2x10^5=520000
6.5x10^4=65000
65000/520000=1/8, or 3 half-lives
3x3=9 days
I'm not the greatest at Chem but this seems more like math than Chem :)
The elements helium neon and Exon are all part of the same _______ on the periodic table.
B. Group
Answer:
Metals and non-metals are substances that can be differentiated on the basis of various physical and chemical properties. Metals are the elements that are generally hard as strong metallic bond exists between the atoms. As against non-metals are the elements which are usually soft.
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1. Remember (sum of products) - (sum of reactants)
So ΔHrxn = 2 ΔHf [H2(g)] + ΔHf [Ca(OH)2(s)] - 2 ΔHf [H2O(l)] - ΔHf [Ca(s)]
= 2*0 + -986.09 kJ/mol - 2*(-285.8 kJ/mol) - 0
Do the math and you'll have the answer. BTW the ΔHf [H2(g)] and ΔHf
[Ca(s)] were 0 because these are elements in their standard states.
</span>HOPE THIS HELPS ;)
