i wanna assume since it has a half life of 5 years, and its been 10 years, that their is 50% left, correct me if im wrong
If 40.0 grams of magnesium is reacted with an excess of nitric acid. 3.3 g of hydrogen gas will be produced.
<h3>What is Stoichiometry ?</h3>
Stoichiometry helps us use the balanced chemical equation to measure quantitative relationships and it is to calculate the amounts of products and reactants that are given in a reaction.
<h3>What is Balanced Chemical Equation ?</h3>
The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.
Now we have to write the balanced equation
Mg + 2HNO₃ → Mg(NO₃)₂ + H₂
According to Stoichiometry
= 3.3 g H₂
Thus from the above conclusion we can say that If 40.0 grams of magnesium is reacted with an excess of nitric acid. 3.3 g of hydrogen gas will be produced.
Learn more about the Stoichiometry here: brainly.com/question/16060223
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The question is in complete, the complete question is:
Which element has an outer electron configuration of s
2
p4
?
(A) Ca (B) Cr (C) Ge (D) Se
Answer:
(D) Se
Explanation:
The outer electronic configuration of an atom reflects the group to which it belongs in the periodic table. Each group has its unique outermost electron configuration and number of electrons found in the outermost shell of the atoms of elements in the group.
s
2
p4 is the unique outermost electron configuration of group 16 elements. Group 16 elements have six electrons in their outermost shell. If we consider the options, only Se is a member of group 16. Hence it is only Se that has the outermost electron configuration s
2
p4
.
The first half reaction is:
Sn+ -> Sn2+
You add 1 electron on the right side:
Sn+ -> Sn2+ + 1e-
The second half reacation is:
Ag+ -> Ag
You add 1 electron to the left side:
Ag+ + 1e- -> Ag
Then, you combine both reactions to get the balanced overall reaction since both half reactions have 1 electrons on the right and left side, respectively. You get:
Sn+ + Ag+ -> Sn2+ + Ag
