A neutral atom is one that has no net charge. In other words, the number of positive charges cancels out with the number of negative charges, so the number of protons equals the number of electrons. Uranium has 92 protons, which means it has a total positive charge of +92. To have a neutral charge, the atom MUST have 92 electrons, as that is a negative charge of -92, and the net charge is ultimately (protons + electrons) = ([+92] + [-92]) = 0.
Answer:
balanced;
unbalanced;
unbalanced;
balanced;
Explanation:
CaO + 3C → CaC2 + CO //all elements are balanced
Na + H2O → 2NaOH + H2 //Na is not balanced on the left
4Fe + O2 → 2Fe2O3 //O is not balanced on the left
2Mg + O2 → 2MgO //left is equal to right, balanced
Answer:
1.4952 grams of sodium bicarbonate she would need to ingest to neutralize this much HCl.
Explanation:
Moles of hydrochloric acid = n
Volume of hydrochloric acid solution = 200.0 mL = 0.200 L
Molarity of the hydrochloric acid = 0.089 M
of HCL
According to reaction, 1 mole of HCl is neutralized by 1 mole of sodium bicarbonate.
Then 0.0178 moles of HCl wil be neutralized by :
of sodium bicarbonate
Mass of 0.0178 moles of sodium bicarbonate:
0.0178 mol × 72 g/mol = 1.4952 g
1.4952 grams of sodium bicarbonate she would need to ingest to neutralize this much HCl.
Answer:
1.) AgNO₃
2.) 0.563 moles AgBr
Explanation:
The limiting reagent is the reagent that is used up completely during a reaction. It can be identified by calculating which reactant produces the smallest amount of product. This can be done by determining the number of moles of each reagent (via molarity conversion). and then converting it to moles of the product (via mole-to-mole ratio).
AgNO₃ (aq) + KBr (aq) ---> AgBr (s) + KNO₃ (aq)
Molarity (M) = moles / liters
100 mL = 1 L
AgNO₃
45.0 mL / 100 = 45.0 L
1.25 M = ? moles / 0.450 L
? moles = 0.563 moles
KBr
75.0 mL / 100 = 0.750 L
0.800 M = ? moles / 0.750 L
? moles = 0.600 moles
In this case, there is no need to use the mole-to-mole ratio because all of the coefficients are one in the reaction (the amount of the limiting reagent used is the same amount of product produced). Since AgNO₃ produces the smaller amount of product, it is the limiting reagent.
The mass decay rate is of the form
where
m₀ = 3000 g,the initial mass
k = the decay constant
t = time, years.
Because the half-life is 30 years, therefore
After 60 years, the mass remaining is
Answer: 750 g
