Answer:
After 3 half lives 10 g of radio active material left.
Explanation:
Given data:
Total amount of radio active material = 80 g
Amount left after 3 half lives = ?
Solution:
At time zero = 80 g
At first half life = 80 g/2 = 40 g
At 2nd half life = 40 g/2 = 20 g
At 3rd half life = 20 g/2 = 10 g
Thus, after 3 half lives 10 g of radio active material left.
How many joules are required to melt 250 grams of water
Answer:
i not sure but i searched it up and it said Q=104525J
Explanation:
Which of the following statements is true?
Question 10 options:
a chromosome is larger than a cell
a DNA strand is made of many chromosomes
a gene contains may chromosomes
a chromosome contains many genes
Answer:
a chromosome contains many genes
Explanation:
Polonium-214 went through a series of radioactive decays to produce a stable isotope of bismuth-210 choose the correct decay series that would produce bismuth-210
A: Polonium-214 undergoes 2 beta decay and 1 gamma emission
B: Polonium-214 undergoes 1 alpha decay and 2 gamma emission
C: Polonium-214 undergoes 2 alpha decay and 1 beta decay
D: Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
The correct decay series :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
Further explanationRadioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,
alpha α particles ₂He⁴ beta β ₋₁e⁰ particles gamma particles ₀γ⁰ positron particles ₁e⁰ neutron ₀n¹Decay's reaction :
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+x+y+z
From this decay reaction can be concluded
mass number decreased by 4
atomic number decreased by 1
Then the most suitable are:
Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.
₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰
So that the mass number and atomic number are the same both before and after decay
Pro
∆G0=-RT in k Known as
Answer:
Gibbs free energy equation
Explanation:
What is the total charge of an iron nucleus
If 18.00 mL of 0.1000 M magnesium hydroxide reacts with 10.00 mL of hydrochloric acid, what is the molarity of the acid solution?
Answer:
0.36M HCl
Explanation:
The reaction of Mg(OH)₂ with HCl is:
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
Where 1 mole of magnesium hydroxide reacts with 2 moles of HCl
To solve this question, we need to find the moles of Mg(OH)₂ that reacted and, with chemical equation, solve for the moles of HCl and its molarity (Using the 10.00mL = 0.01000L) as follows:
Moles of Mg(OH)₂:
18mL = 0.018L * (0.100mol / L) = 0.0018 moles Mg(OH)₂
Moles HCl:
0.0018 moles Mg(OH)₂ * (2 moles HCl / mol Mg(OH)₂) = 0.0036 moles HCl
Molarity HCl:
0.0036 moles HCl / 0.0100L =
0.36M HClwhat is made from a chemical reaction?
Answer:
the Product
Explanation:
How many mL of 0.125 M Ba(OH)2 would be required to completely neutralize 75.0 mL of 0.845 M HCl? What is the pH of the solution at the equivalence point?
Answer:
253.5mL of Ba(OH)₂ are required to neutralize the HCl solution
The pH at equivalence point is = 7
Explanation:
The reaction of Ba(OH)₂ with HCl is:
Ba(OH)₂ + 2HCl → BaCl₂ + 2H₂O
First, we need to find moles of HCl. With these moles and the chemical equation we can find the moles of Ba(OH)₂ and the volume required:
Moles HCl:
75.0mL = 0.075L * (0.845mol / 1L) = 0.063375moles HCl
Moles Ba(OH)₂:
0.06338moles HCl * (1mol Ba(OH)₂ / 2mol HCl) = 0.03169 moles Ba(OH)₂
Volume of the 0.125M Ba(OH)₂:
0.03169 moles Ba(OH)₂ * (1L / 0.125mol) = 0.2535L are required =
253.5mL of Ba(OH)₂ are required to neutralize the HCl solution
As the titration was of a strong acid, HCl, with a strong base, Ba(OH)₂, the pH at equivalence point is = 7
what is the molarity of a solution made by adding 0.720 mole of NaOH to 2.40 liters of water
Answer:
Molarity = 0.3 M
Explanation:
Given data:
Moles of NaOH = 0.720 mol
Volume of water = 2.40 L
Molarity = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Molarity = 0.720 mol / 2.40 L
Molarity = 0.3 mol/L
Molarity = 0.3 M
A candle made of certain wax blend burns at a rate of 44.2 mg/min. What is the value of this burn rate if expressed in grams/hour
Answer:
2.652 g/h.
Explanation:
Burn rate (in mg/min) = 44.2 mg/min
Burn rate (in m/h) =?
We'll begin by converting 44.2 mg/min to g/min. This can be obtained as follow:
1 mg/min = 0.001 g/min
Therefore,
44.2 mg/min = 44.2 mg/min × 0.001 g/min / 1 mg/min
44.2 mg/min = 0.0442 g/min
Finally, we shall convert 0.0442 g/min to g/h. This can be obtained as follow:
1 g/min = 60 g/h
Therefore,
0.0442 g/min = 0.0442 g/min × 60 g/h / 1 g/min
0.0442 g/min = 2.652 g/h
Therefore, 44.2 mg/min is equivalent to 2.652 g/h.
Thus, the burn rate (in m/h) is 2.652 g/h.
These allow electricity to flow easily through them (think copper and aluminum).
(Lessons 5.01-5.03)
Insulators
Electric Currents
Conductors
Resistors
Answer:
conductors
Explanation:
A 12.0% sucrose solution by mass has a density of 1.05 gem, what mass of sucrose is present in a 32.0-mL sample of this solution?
A) 0.126g
B) 3.66g
C) 4.03g
D) 3.84g
E) 280 g
Answer:
Option C. 4.03 g
Explanation:
Firstly we analyse data.
12 % by mass, is a sort of concentration. It indicates that in 100 g of SOLUTION, we have 12 g of SOLUTE.
Density is the data that indicates grams of solution in volume of solution.
We need to determine, the volume of solution for the concentration
Density = mass / volume
1.05 g/mL = 100 g / volume
Volume = 100 g / 1.05 g/mL → 95.24 mL
Therefore our 12 g of solute are contained in 95.24 mL
Let's finish this by a rule of three.
95.24 mL contain 12 g of sucrose
Our sample of 32 mL may contain ( 32 . 12) / 95.24 = 4.03 g
Write the formula for diphosphorous pentoxide
Answer:
P4O10
Explanation:
