The question is incomplete, here is the complete question:
The half-life of a certain radioactive substance is 46 days. There are 12.6 g present initially.
When will there be less than 1 g remaining?
Answer: The time required for a radioactive substance to remain less than 1 gram is 168.27 days.
Step-by-step explanation:
All radioactive decay processes follow first order reaction.
To calculate the rate constant by given half life of the reaction, we use the equation:
[tex]k=\frac{0.693}{t_{1/2}}[/tex]
where,
[tex]t_{1/2}[/tex] = half life period of the reaction = 46 days
k = rate constant = ?
Putting values in above equation, we get:
[tex]k=\frac{0.693}{46days}\\\\k=0.01506days^{-1}[/tex]
The formula used to calculate the time period for a first order reaction follows:
[tex]t=\frac{2.303}{k}\log \frac{a}{(a-x)}[/tex]
where,
k = rate constant = [tex]0.01506days^{-1}[/tex]
t = time period = ? days
a = initial concentration of the reactant = 12.6 g
a - x = concentration of reactant left after time 't' = 1 g
Putting values in above equation, we get:
[tex]t=\frac{2.303}{0.01506days^{-1}}\log \frac{12.6g}{1g}\\\\t=168.27days[/tex]
Hence, the time required for a radioactive substance to remain less than 1 gram is 168.27 days.
Philip George and matt are water polo players. The diagram below represents the players positions during a game
What is the measure of the angle at George’s position
A. 6°
B. 37°
C. 60°
D. 83°
Answer:
It 6
Step-by-step explanation:
Answer:
83 degrees
Step-by-step explanation:
10x+23+8x+12+55-3x=180
15x=90
x=6
10(x)+23 is George's position angle
10(6)+23 =83 degrees
A store is having a special on candy bars. The special is 4 boxes of candy bars for $11.00. Which statement about the box of candy bars is true?
Answer:
answer is c (2.75)
Step-by-step explanation:
What is the coefficient in -x^2?
Answer:
-x i belive it might just be x tho
Step-by-step explanation:
What is the measure of x
Answer:
x = 75°
Step-by-step explanation:
From the figure it appears that:
[tex] m\angle B = 36\degree [/tex]
and
[tex] m\angle D = 39\degree [/tex]
x is the measure of the exterior angle of [tex] \triangle BDH[/tex]
Therefore, by exterior angle theorem:
[tex] x = m\angle B+ m\angle D [/tex]
[tex] x = 36\degree+ 39\degree [/tex]
[tex] x =75\degree [/tex]
2x2+3x-14=0 Does anyone know the answer?
Answer:
Answers l thenk (1.16)
Mmmmm
In a hotel, Elevator 1 stops at the third floor at an elevation of 40ft. Elevator 2 stops at the parking level at an elevation of -25ft.
How far apart, in feet, are the two elevators? Show or explain your work.
PLEASEEE ANSWER!!!
Answer:
65 ft
Step-by-step explanation:
Negative and positive numbers can be expressed as how far away they are from zero.
40 is 40 units away from zero. Elevator 1 is 40 units from 0.
-25 is 25 units away from zero. Elevator 2 is 25 units from 0.
To find the distance, we'll add their distances from 0.
40 + 25 = 65
They are 65 units apart. In your problem you specify feet, so they are 50 ft apart.
Choose the equation and the inequality needed to answer this question. Trevor tutors French for $15 and hour and scoops ice cream for $10 an hour. He is going to work 15 hours this week. At least how many hours does he need to tutor to make more than $180? Let x equal the number of hours he tutors and y be the number of hours he scoops ice cream.
Answer:
One second let me look it up for u :)
Step-by-step explanation:
Answer:
Total number of hours = 15
Let the hours spent tutoring french be x.
Therefore hours spent on scooping ice cream = (15 - x)
Amount: Tutoring french is $15 an hour, total for x hours = 15x
For scooping ice cream it is $10 an hour 10*(15 - x) = 150 - 10x
To make more than $180
15x + (150 - 10x) > 180
15x + 150 - 10x > 180
15x - 10x > 180 - 150
5x > 30
x > 30/5
x > 6
trevor needs to tutor 6 hours to make more than 180
Step-by-step explanation:
I hope this helped :)
What is the probability of rolling a multiple of 3 on a 6-sided die?
Answer:
33% or 1/3 ...............
Which decimal is less than 0.47
(0.38) (0.9) (0.64) (0.5)
Answer:
0.5
Step-by-step explanation:
just divide in a calculator
Answer:
0.38
Step-by-step explanation:
Look at the tenths decimal place to compare
3 is less than 4
9 is greater than 4
6 is greater than 4
5 is greater than 4
The only one less than 4 is 3 which corresponds to the decimal 0.38
helpppp nowww plsss!!
Answer:
6/10
Step-by-step explanation:
6/10
Write the negation of the proposition.
Some people don't like walking.
Answer: All people do like walking
It might be more grammatically correct to say "all people like walking", but I wanted to include the "do" in there because we can see how the "don't" flips to "do". The "some" flips to "all" as well.
The negation of a statement is the complete opposite in every way. If a friend makes a claim that some people don't like walking, and you can prove that all people do like walking, then this contradicts your friend. The same can be said in reverse: if your friend claims "all people do like walking", then you can counter back with "some people don't like walking". All it takes is one counter-example to prove the claim "some people don't like walking" to be correct. In terms of logic, the word "some" means "one or more".
35 percent as a decimal
simplify the expression-14-(-8)
Answer:
the answer is -6
Step-by-step explanation:
-14-(-8)=-6.
Answer:
[tex] - 14 - ( - 8) \\ \\ - 14 +8 \\ \\ = - 6[/tex]
There are 1250 students at Cypress Middle School. 42% of the students are enrolled in PE. How many students are enrolled in PE?
Answer:
The answer is 525 students.
Step-by-step explanation:
1250 total students
42% = PE
42% of 1250 = [tex]525[/tex]
Thus, the answer is 525.
Answer: 525 students are enrolled in PE.
Step-by-step explanation:
What would this be?!?
Answer:
It's C
3 and 3/4
Step-by-step explanation:
1 dozen=12
2 dozens=24
1 1/2 divided by 24 = 1/16
1/16 times 60
3 and 3/4
The large rectangle below represents one whole.
What percent is represented by the shaded area?
%
Jose has $20 and is saving $6 per week. Ana has $150 and is spending $4 per
week. When will they both have the same amount of money?
Which order pairs are solution to the inequality Y-3x<-8
Answer:
your answer are c and d hope it helps .
To decorate her bedroom, Lisa spent $62.89 on new bedding, $48.26 on paint, and $81.99 on accessories. About how much did she spend to decorate her bedroom? (1 point)
Question 3 options:
1)
$190
2)
$210
3)
$230
4)
$300
Answer:
3 because it makes a of sense
Step-by-step explanation:
Evaluate the following: (½)(10) −(−12) −25
Answer:
-8
Step-by-step explanation:
1/2 times 10 is 5. and a negative times a negative is a positive, so you have a positive 12, which becomes 5+12-25, which is -8
Use this table to match the molecules with their estimated masses.
Atom Mass (in grams)
hydrogen 1.67 × 10-24
oxygen 2.66 × 10-23
carbon 1.99 × 10-23
nitrogen 2.32 × 10-23
Answer:
7.31 x 10^-23
Answer: CO2 (1 atom of carbon and 2 atoms of oxygen)
3.34 x 10^-24
Answer: H2 (2 atoms of hydrogen)
2.821 x 10^-23
Answer: NH3 (1 atom of nitrogen and 3 atoms of hydrogen)
7.64 x 10^-23
Answer: NO2 (1 atom of nitrogen and 2 atoms of oxygen)
Step-by-step explanation:
hope this helps :)
7.31 x 10^-23 = CO2 i.e. 1 atom of carbon and 2 atoms of oxygen
3.34 x 10^-24 = H2 (2 atoms of hydrogen)
2.821 x 10^-23 = NH3 (1 atom of nitrogen and 3 atoms of hydrogen)
7.64 x 10^-23 = NO2 (1 atom of nitrogen and 2 atoms of oxygen)
Learn more: https://brainly.com/question/4804019?referrer=searchResults
hi help me who is genius this question what are acc that should be Cr and Dr and how will the ledger will be done also a little help will be helpfull
In ANOP, NP is extended through point P to point Q,
mZOPQ = (6x – 15)°, mZPNO = (2x + 18)°, and
mZNOP = (2x – 13). What is the value of x?
Answer:
x = 10
Step-by-step explanation:
Form the information given, we can deduce that:
m<OPQ is an exterior angle of ∆NOP = (6x - 15)°
m<PNO = (2x + 18)° and m<NOP = (2x - 13)° are both interior angles that are opposite to the exterior angle.
Therefore, based on the exterior angle theorem:
m<OPQ = m<PNO + m<NOP
(6x - 15)° = (2x + 18)° + (2x - 13)°
Solve for x
6x - 15 = 2x + 18 + 2x - 13
6x - 15 = 4x + 5
6x - 15 - 4x = 4x + 5 - 4x (Subtraction property of equality)
2x - 15 = 5
2x - 15 + 15 = 5 + 15 (addition property of equality)
2x = 20
2x/2 = 20/2 (division property of equality)
x = 10
Jordyn's rectangular garden is represented in the diagram below. If a diagonal walkway crosses their garden, what is its length, in feet?
Walkway
8 feet
15 feet
Answer: 23
Step-by-step explanation:
Write an equivalent expression
8x - 6x + 10y + 6 + 4y + 9 = ?x + ?y + ?
Answer: 2x + 14y + 15
Step-by-step explanation:
8x - 6x + 10y + 6 + 4y + 9
Bring like terms together
8x - 6x + 10y + 4y + 6 + 9
Combine like terms
2x + 14y + 15
Hope this helped!
expend log10 (x³y⁵)
Answer:
3log(x) + 5log(y)
Step-by-step explanation:
[tex] log({x}^{3} {y}^{5} ) \\ = log( {x}^{3} ) + log( {y}^{5} ) \\ = 3 log(x) + 5 log(y) [/tex]
Which statements are true? Check all that apply.
On a coordinate plane, point A is (2, 3), point B is (3, 2), point C is (negative 2, 2), point D is (negative 3, negative 3), point E is (0, 3), point F is (2, 0), and point G is (0, 0).
A is in Quadrant I.
B is on the x-axis.
C is in Quadrant I.
D is in Quadrant III.
E is on the x-axis.
F is on the x-axis.
G is on the y-axis. Please anwser quick!!!!
Given:
A(2, 3)B(3, 2)C(-2, 2)D(-3, -3)E(0, 3)F(2, 0)G(0, 0)Let's first understand the different signs and different quadrants.
Quadrant I: (+, +)Quadrant ll: (-, +)Quadrant III: (-, -)Quadrant IIII: (+, -)Verifying them with the given points,
A is in Quadrant I. - TRUEB is on the x-axis. - FALSEC is in Quadrant I. - FALSED is in Quadrant III. - TRUEE is on the x-axis. - FALSEF is on the x-axis. - TRUEG is on the y-axis. - FALSEHope it helps. :)
Answer:
A D F
Step-by-step explanation:
All credit to him
Please solve the question below
Answer:
AB = 14 units
∠F = 39°
Step-by-step explanation:
Given:
ΔABC ≅ ΔDEF
So,
AB = ED (By CPCT)
So,
AB = 14 units
∠C = ∠F (By CPCT)
∠F = 39°
What value of x makes the equation true 7+2x=4x-5
Answer:
6
Step-by-step explanation:
Fact
Answer:
x=6
Step-by-step explanation:
1. 7+2x=4x-5
2. 7+2x-2x=4x-5-2x
7=2x-5
12=2x
x=12/2
x=6
Use the ALEKS calculator to find 62% of 80. Do not round your answer.
Answer:
ok Naruto
Step-by-step explanation:
49.6