answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Dovator [93]
2 years ago
11

The half life of radium 226 is 1602 years. if you have 500 grams of radium today how many grams would have been present 9612 yea

rs ago?
Chemistry
1 answer:
slavikrds [6]2 years ago
6 0
Half life is the time taken by a radio active isotope to reduce by half of its original amount. Radium-226 has a half life of 1602 years meaning that it would take 1602 years for a mass of radium to reduce by half.
Number of half lives in 9612 years = 9612/1602 = 6 half lives
New mass = Original mass x (1/2)n where n is the number of half lives.
Therefore, New mass= 500 x (1/2)∧6
                                  = 500 x 0.015625
                                  = 7.8125 g
Hence the mass of radium after 9612 years will be 7.8125 grams.
You might be interested in
A 5.00 mL sample of H3PO4 solution of unknown concentration is titrated with a 0.1090 M NaOH solution. A volume of 7.12 mL of th
babunello [35]
The answer is that first you add 5.00+7.12=12.12
6 0
2 years ago
Robyn has been working on developing a new task to test the reaction time of athletes. As she begins to test athletes using her
umka2103 [35]

Answer:

Ceiling effect

Explanation:

A ceiling effect takes place when the test items are not challenging enough for a group of individuals. Thus, the test score will not increase for a subsample of people who may have improved because they have already attained the highest score that can be achieved on that test.

6 0
2 years ago
An object accelerates 3.0 m/s2 when a force of 6.0 Newton’s is applied to it. What is the mass of the object?
Alekssandra [29.7K]

Answer:2kg

Explanation:

Mass =?

Acceleration = 3.0 m/s2

Force = 6.0N

Force = Mass x Acceleration

6 = Mass x 3

Mass =6/3 = 2Kg

6 0
2 years ago
The activation energy for the reaction NO2(g)+CO(g)⟶NO(g)+CO2(g) is Ea = 375 kJ/mol and the change in enthalpy for the reaction
HACTEHA [7]
Answer: 625 kj/mol

Explanation:

As shown below this expression gives the activation energy of the reverse reaction:

EA reverse reaction = EA forward reaction + | enthalpy change |

1) The activation energy, EA is the difference between the potential energies of the reactants and the transition state:

EA = energy of the transition state - energy of the reactants.

2) The activation energy of the forward reaction given is:

EA = energy of the transition state - energy of  [ NO2(g) + CO(g) ] = 75 kj/mol

3) The negative enthalpy change - 250 kj / mol for the forward reaction means that the products are below in the potential energy diagram, and that the potential energy of the products, [NO(g) + CO2(g) ] is equal to 375 kj / mol - 250 kj / mol = 125 kj/mol

4) For the reverse reaction the reactants are [NO(g) + CO2(g)], and the transition state is the same than that for the forward reaction.

5) The difference of energy between the transition state and the potential energy of [NO(g) + CO2(g) ] will be the absolute value of the change of enthalpy plus the activation energy for the forward reaction:

EA reverse reaction = EA forward reaction + | enthalpy change |

EA reverse reaction = 375 kj / mol + |-250 kj/mol | = 375 kj/mol + 250 kj/mol = 625 kj/mol.

And that is the answer, 625 kj/mol
4 0
2 years ago
The volume of a single strontium atom is 4.15×10-23 cm3. What is the volume of a strontium atom in microliters
Ivenika [448]

Answer:-  4.15*10^-^2^0\mu L

Solution:- It is a volume unit conversion problem where we are asked to convert the volume from cm^3 to microliters.

We know that:

1cm^3 = 1 mL

1mL=10^-^3L

and, 1L=10^6\mu L

Let's use these conversions factors for the desired conversion using dimensional as:

4.15*10^-^2^3cm^3(\frac{1mL}{1cm^3})(\frac{10^-^3L}{1mL})(\frac{10^6\mu L}{1L})

= 4.15*10^-^2^0\mu L

So, the answer is  4.15*10^-^2^0\mu L .

7 0
2 years ago
Other questions:
  • In which region are most particles moving the fastest?
    12·2 answers
  • Please help 30 pts!!!!! A friend needs these answers and I don't know what to say. If you don't know the answer, please ask some
    8·1 answer
  • Determine the volume of hexane that contains 5.33 × 1022 molecules of hexane. The density of hexane is 0.6548 g/ml and its molar
    10·1 answer
  • The partial pressures in an equilibrium mixture of NO, Cl2, and NOCI at 500 K are as follows: PNo = 0.240 atm, Pel2 = 0.608 atm,
    9·1 answer
  • Harmful chemicals released directly into the atmosphere due to either human activities or natural processes are ___ air pollutan
    7·1 answer
  • The isotopes of an element all have the same __(atomic, mass) __number, but they have different __(atomic,mass)__numbers.
    6·1 answer
  • Lastly, Snape thinks we should try one more calculation. What is the retention factor if the distance traveled by the solvent fr
    8·1 answer
  • An experimenter studying the oxidation of fatty acids in extracts of liver found that when palmitate (16:0) was provided as subs
    9·1 answer
  • The human body burns glucose for energy according to this chemical reaction: The products of the reaction are carbon dioxide and
    11·1 answer
  • A deck of cards has dimensions 8.9cm x 5.72cm x 1.82 cm. What is the volume of the deck in cubic centimeters?
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!