Hey! Your answer would be the appearance and disappearance of group of organisms
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That will make a gold-202 nucleus.
<h3>Explanation</h3>
Refer to a periodic table. The atomic number of mercury Hg is 80.
Step One: Bombard the
with a neutron
. The neutron will add 1 to the mass number 202 of
. However, the atomic number will stay the same.
- New mass number: 202 + 1 = 203.
- Atomic number is still 80.
.
Double check the equation:
- Sum of mass number on the left-hand side = 202 + 1 = 203 = Sum of mass number on the right-hand side.
- Sum of atomic number on the left-hand side = 80 = Sum of atomic number on the right-hand side.
Step Two: The
nucleus loses a proton
. Both the mass number 203 and the atomic number will decrease by 1.
- New mass number: 203 - 1 = 202.
- New atomic number: 80 - 1 = 79.
Refer to a periodic table. What's the element with atomic number 79? Gold Au.
.
Double check the equation:
- Sum of mass number on the left-hand side = 203 = 202 + 1 = Sum of mass number on the right-hand side.
- Sum of atomic number on the left-hand side = 80 = 79 + 1 = Sum of atomic number on the right-hand side.
A gold-202 nucleus is formed.
Answer:
0.142 M
Explanation:
Let's consider the neutralization reaction between calcium hydroxide and hydrochloric acid.
Ca(OH)₂ + 2 HCl → CaCl₂ + 2 H₂O
25.8 mL of 0.183 M HCl are used. The reacting moles are:
0.0258 L × 0.183 mol/L = 4.72 × 10⁻³ mol
The molar ratio of Ca(OH)₂ to HCl is 1:2. The reacting moles of Ca(OH)₂ are 1/2 × 4.72 × 10⁻³ mol = 2.36 × 10⁻³ mol
2.36 × 10⁻³ moles of Ca(OH)₂ are contained in 16.6 mL. The molarity of Ca(OH)₂ is:
M = 2.36 × 10⁻³ mol/0.0166 L = 0.142 M