Answer:
The period 4 alkaline-earth metal has the name Calcium. An isotope of this element having 20 neutrons has a mass number of 40.
Explanation:
Looking at the periodic table 4th row for the alkaline-earth metal, we can find Calcium which has an atomic number of 20 (or protons number, or z). The mass number is given by the sum of protons and neutrons. If the number of protons in this case is 20 and the number of neutrons is also 20, the mass number A = 40.
Answer:
212.5 mL
both the original and the diluted solution have 0.765 moles of KCl
Explanation:
c1V1 = c2V2
V2 = c1V1/c2 = (1.8 M×425 mL)/1.2 M = 637.5 mL
(637.5 - 425) mL = 212.5 mL
n = (1.8 mol/L)(0.425 L) = 0.765 moles of KCl
since it's a dilution, the diluted solution has the same number of moles as the original solution, 0.765 moles of KCl
Answer:
C8H8 + 10O2 → 8CO2 + 4H2O
Explanation:
unbalanced reaction:
C8H8 + O2 → CO2 + H2O
balanced for semireactions:
(1) 16H2O + C8H8 → 8CO2 + 40H+
(2) 10(4H+ + O2 → 2H2O)
⇒ 40H+ + 10O2 → 20H2O
(1) + (2):
balanced reaction:
⇒ C8H8 + 10O2 → 8CO2 + 4H2O
8 - C - 8
20 - O2 - 20
8 - H - 8
Most likely to be found is called an Orbital.
