A sample of pure radioactive isotope is left to decay. After 40.0 days, the 1 point
sample is placed in a mass spectrometer, and it is determined that only
25% of the original isotope remains. How long is the half-life?

Answers

Answer 1

Answer:

6 months and 1 day

Explanation:


Related Questions

What do the red arrows represent

Answers

Answer:

There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.

What elements are present NaAl(SO4) in one of the components of baking powder?

Answers

Answer:

1 Sodium, 1 Aluminum (1 Sulfur, 4 Oxygen)

Explanation:

hope that helps

Which of the following is a polar molecule?
A. A linear Carbon dioxide molecule (C02)
B. A carbon monoxide molecule (CO)
C. A calcium oxide molecule (CaO)
D. An oxygen molecule (02)

Answers

Answer:

B. A carbon monoxide molecule(CO)

Explanation:

CO is polar because oxygen is more electronegative than carbon, so it gives oxygen a partial negative charge and carbon and partial positive charge. This causes a net dipole moment. CO2 is linear with no net dipole moment because each C-O bond is equal and opposite to each other, so they equal 0, which makes them non polar.

The answer will be (B) hope this helps!

Build Carbon (6 red protons, 6 grey neutrons, 6 blue electrons) How many
neutrons could an isotope of carbon have?
A. 5
B. 6
C. 7

Answers

B I think sorry if it’s wrong (;

Answer:

B. 6

Explanation:

Isotope given:

                      ¹⁴₆C

In specie written as this;  

  Superscript  = Mass number

  Subscript  = Atomic number

To find the protons, it is the same as the atomic number;

               Protons  = Atomic number  = 6

Neutrons have no charges;

Neutrons  = Mass number - Atomic number  =

 Neutrons  = 14 - 6  = 8

The number of electrons is the same as the atomic number = 6

WILL GIVE BRAINLIEST TO PERSON WHO ANSWERS FASTEST AND CORRECT BUT ANY ANSWERS TO JUST GET POINTS WILL GET REPORTED AND DELETED

Which is an example of condensation? *
5 points
A) water boiling in a pot
B) water being absorbed by plants
C) salt being removed from water
D) moisture on a mirror after a hot shower

Answers

Answer:

a

Explanation:

Answer:

D

Explanation:

Please help me this is my science final

Answers

Answer:

1.Winter

2.Autmn

3.Summer

4.Spring

I hope this helps!

1- winter
2- autumn
3- summer
4- spring

Which of the following characteristics is NOT used to classify organisms into groups?
a.
nucleus or no nucleus
c.
color or no color
b.
autotroph or heterotroph
d.
unicellular or multicellular

Answers

Answer:

b

Explanation:

Which of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.

Answers

Answer:

3

Explanation:

It is based on empirical evidence

The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.

What is a hypothesis?

Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.

It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis

The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.

Learn more about hypothesis,here:

https://brainly.com/question/13025783

#SPJ5

pls answer i need it now!! I will give brainliest to the best answer!!

Answers

Answer:

sample 2

Explanation:

hope this helps

the answer is B i think

Stephanie the Skydiver has a mass of 48kg, what is the force that she
exerts as she is falling to the ground?

Answers

Answer:

470.4N

Explanation:

Given parameters:

Mass of Stephanie  = 48kg

Unknown:

Force she exerts while falling to the ground  = ?

Solution:

The force she exerts is her weight;

  Weight  = mass x acceleration due to gravity

  Now insert the parameters ands solve ;

  Weight  = 48 x 9.8 = 470.4N

help me please with my science test questions 5 and 6​

Answers

Answer:

5. Element J has the highest atomic number

6. Elements G and L have the same number of electrons in their outermost shell.

Explanation:

The periodic table of elements is a table which shows the arrangement of the elements in the order of increasing atomic number. Starting from the topmost left-hand side of the table where the element with the least atomic number is placed, and going across the table from left to right and down to the lowest point to the right of the table, where the element with the highest atomic number is located, the atomic number of elements progressively increases.

Looking at the table, it can be seen that the element J is found at the lowest point to the right of the table. Therefore, element J has the highest atomic atomic number.

6. In the periodic table, elements are arranged into groups and periods. The groups are the columns while the periods are the rows. Elements in the same column or group have the same number of electrons in their outermost shell. Therefore, element G and L have the same number of electrons in their outermost shell.

A 1.0 kg ball is thrown into the air and initial velocity of 30 mi./s how high into the air did the ball travel

Answers

Answer:

45.9m

Explanation:

Given parameters:

Mass of the ball  = 1kg

Initial velocity  = 30m/s

Unknown:

Height the ball will travel  = ?

Solution:

At the maximum height, the final velocity of the ball  will be 0;

  Using ;

   V²   = U²   - 2gh

V is the final velocity

U is the initial velocity

g is the acceleration due to gravity

h is the height

     0² = 30²   - (2 x 9.8 x h)

    0 = 900 - 19.6h

      h  = 45.9m

"30 mph north" is an example of:
O velocity
speed
distance
O displacement

Answers

Answer:

distance velocity displacement, all three

Explanation:

What is the percent composition of nitrogen in N 2 O

Answers

Answer:

63.6%

Explanation:

The given compound is:

     N₂O;

The problem here is to find the percent composition of nitrogen in the compound.

First find the molar mass of the compound:

 Molar mass of N₂O = 2(14) + 16  = 44g/mol

So;

 Percentage composition of Nitrogen  = [tex]\frac{2 x 14}{44}[/tex]  x 100  = 63.6%

What is the frequency of light with a wavelength of 3.2 x 10^-16 m?

Answers

Answer:

f = 0.94 ×10²⁴  Hz

Explanation:

Given data:

Frequency of light = ?

Wavelength of light = 3.2 ×10⁻¹⁶ m

Solution:

Formula:

Speed of light = wavelength × frequency

c = λ × f

c = speed of wave = 3×10⁸ m/s

by putting values,

3×10⁸ m/s  = f × 3.2 ×10⁻¹⁶ m

f  =  3×10⁸ m/s   / 3.2 ×10⁻¹⁶ m

f  = 0.94 ×10²⁴ s⁻¹

f = 0.94 ×10²⁴  Hz (Hz = s⁻¹)

How many hydrogen atoms are there in 2 molecules of C3H6?​

Answers

Answer:

there are 12 hydrogen atoms in 2 molecules of C3H6

Explanation:

Cynthia has 200kg of magnesium. Calculate how much MgCl2 she can make.

Mg + Cl2 = MgCl2

Answers

Answer:

784.4kg

 

Explanation:

Given parameters:

Mass of Mg  = 200kg

Unknown:

Mass of MgCl₂  = ?

Solution:

  The reaction equation is given as:

            Mg  +  Cl₂ →   MgCl₂

Find the number of moles of the given specie;

  Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex]   = [tex]\frac{200000}{24.3}[/tex]   = 8230.5mole

So;

   1 mole of Mg will produce 1 mole of MgCl₂

 

   8230.5mole of Mg will produce 8230.5mole of MgCl₂

Mass of MgCl₂   = number of moles x molar mass

                    Molar mass of MgCl₂  = 24.3 + 2(35.5) = 95.3g/mol

 Mass of MgCl₂   = 8230.5mole x  95.3g/mol  = 784.4kg

 

Making Sense
1. School bus drivers are extra careful when they cross railroad tracks. They stop before they cross railroad tracks to be sure that there is no
train coming. Yet, trains typically move more slowly through towns than cars do. If trains usually move more slowly than cars, why can
they do more damage if they hit something in their path?
=
2
11
B
1
GO
III
un
III
X2
Saved January 15, 2021 07:35:00 PM

Answers

Answer: I think that trains move faster then cars! Buttt, The trains are much stronger and bigger, then cars or trucks. Even if they move slowly they can still crush something smaller then them.

Explanation: ( didnt really understand the question, but i tried)

help me please just w number 2&3

Answers

Answer:

2.No. because in an open system, gas will blow up & so, if it's measured, it won't have the equal amount of the reactant. But, if you arrange this reaction in a closed system, then it will be the same.

3.2SiO2+4Cl2= 2SiCl4+O2

Explanation:

Carbon dioxide is used by plants for ___?​

Answers

Answer:

photosynthesis

Explanation:

that's the way plants feed themselves

Answer:

photosynthesis

Explanation:

I hope i helped

what is one example of a electromagnetic wave

Answers

Answer:

Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Answer:

Electromagnetic waves can be split into a range of frequencies. This is known as the electromagnetic spectrum. Examples of EM waves are radio waves, microwaves, infrared waves, X-rays, gamma rays, etc.

Explanation:

when an electron gets closer to the nucleus does the attraction or repulsion grow weaker or stronger?

Answers

Answer:

Weaker

Explanation:

Since the charges on nucleus and electron are opposite in nature, an attractive force exists between them. It is true in generally, that when objects are made to move closer together in the direction of an attractive force, potential energy decreases (and increases whenever attracting objects are force to move apart).

Here, we are required to determine if the attraction or repulsion grow weaker or stronger.

When electrons get closer to the nucleus, the attraction grows stronger.

First, we must establish scenarios when there can be attraction and ones where there can be repulsion.

By the law guiding electric charges; In electrical interactions:

Like poles repel while Unlike poles attract.

Also, in the atomic model; the nucleus is positively charged as it contains protons (+vely charged) and neutrons which are uncharged particles.

Since the nucleus is positively charged and the electrons revolve round their orbit. Therefore, the force is an attraction force.

As we all know that the force of attraction or of repulsion as the case may be is inversely proportional to the distance between the charged particles (the electrons and the nucleus in this case)

When an electron gets closer to the nucleus, the distance between the electron and the nucleus reduces; and the force of attraction between the electron and the nucleus increases.

Ultimately, when an electron gets closer to the nucleus, the attraction force will grow stronger due to the reduced distance between the electron and the nucleus.

Read more:

https://brainly.com/question/20822622

A student performed an investigation to determine if the rate of photosynthesis in elodea is affected by a higher than normal concentration of carbon dioxide gas in the water in which the plant is growing. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant. In this investigation, what would be the best indicator of the rate of photosynthesis? a a change in the color of the plant b an increase in the length of the elodea plant over a period of 12 hours c the amount of light that is transmitted through the water d the amount of oxygen collected over a period of 12 hours

Answers

Answer:

D. the amount of oxygen collected over a period of 12 hours

Explanation:

Photosynthesis is a metabolic reaction performed by the cells of plant. In this reaction, light is used as an energy source to combine carbon dioxide (CO2) and water (H2O) to produce glucose and oxygen gas (O2) as products. In every chemical reaction including photosynthesis, an increase in concentration of reactants will increase the rate of the reaction, which is evident in the amount of products formed.

According to this question where a student is performing an investigation to determine the relationship between a higher than normal concentration of carbon dioxide gas and the rate of photosynthesis. After increasing the concentration of carbon dioxide in water, the student illuminated the plant with a light and collected the bubbles of oxygen gas that were given off from the cut end of the submerged plant.

Based on the above explanation, the best indicator of the rate of photosynthesis in this investigation will be THE AMOUNT OF OXYGEN COLLECTED OVER A PERIOD OF 12 HOURS.

can we seperate naphthalene from sugar by filtration to obtain pure sugar?​

Answers

Yes, distillation is the process by which sugar can be separated from the sugar solution.

Answer:

As Naphthalene undergoes sublimation, we use sublimation process. On condensing naphthalene can be separated.

please help!! I’m really confused because it’s actually supposed to be called occluded front but the definition is true.

Answers

I believe it is False

The element fluorine has an atomic number of
a. 10
b. 9
c. 19
d. 28

Answers

Answer:

B.9

Explanation:

It has a atomic number of 9

Which of the following correctly shows the relationship, in terms of number of particles, of the three substances?

A. 1 mole of water < 1 mole of helium < 1 mole of aluminum

B. 1 mole of aluminum = 1 mole of helium = 1 mole of water

C. 1 mole of aluminum < 1 mole of helium < 1 mole of water

D. 1 mole of helium < 1 mole of aluminum < 1 mole of water​

Answers

The answer is b but I’m not sure

The correct option which shows the relation between particles of the three substances is 1 mole of aluminum = 1 mole of helium = 1 mole of water.

What is a particle?

A particle is a small part of matter.

The term refers to particles of all sizes, ranging from subatomic particles like electrons to visible particles like dust particles floating in sunlight.

The relationship of a number of particles of the substance can be calculated by Avogadro's law

Thus, the correct option is B. 1 mole of aluminum = 1 mole of helium = 1 mole of water

Learn more about particles

https://brainly.com/question/1685421

Does it take shorter or longer time to travel when the velocity is low?

Answers

Answer:

yes

explanation:

yes because when the velocity is low, all the energy is low and nothing can't do nothing without energy

a sample of methane gas at a pressure of 0.727 atm and a temperature of 26.9 occupies a volume of 726 ml. if the gas is allowed to expand at constant temperature until its pressure is 0.412 atm, the volume of the gas sample will be _ mL

Answers

Answer:

1280L

Explanation:

Given parameters:

Initial pressure  = 0.727atm

Temperature  = 26.9°C

Initial volume  = 726mL  = 0.726L

New pressure  = 0.412atm

Unknown:

New volume of the gas sample  = ?

Solution:

To solve this problem, we apply boyles law;

            P1V1  = P2V2

P and V are pressure and temperature

1 and 2 are initial and new state

             0.727 x 0.726  = 0.412 x V2

                   V2  = 1.28mL  = 1280L

Give an example of a chemical reaction during which a single substance breaks
down. *

Answers

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

Electrolysis of melt NaCl to form sodium (Na) metal and chlorine (Cl₂) gas.

This is a class of reaction called 'Decomposition Rxns'. For what it's worth, there are 6 distinct compound types that undergo breakdown by decomposition. The acronym C O A C H E can help remember them.

C - Carbonates => CaCO₃(s) => CaO + CO₂

O - Oxides of Metals => 2Fe₂O₃(s) => 4Fe°(s) + 3O₂(g)

A - Acids (Oxoacids) => H₂CO₃(aq) => CO₂(g) + H₂O(l)

C - Chlorates, Bromates & Iodates => 2KClO₃(s) => 2KCl(s) + 3O₂(g)

H - Hydroxides => Ca(OH)₂(s) => CaO(s) + H₂O(l)

E - Electrolysis => see above electrolysis of NaCl(l)

Answer:

2NaCl(l) => 2Na(s) + Cl₂(g)

Explanation:

Other Questions
Victoria's favorite cookie recipe uses 170 grams of butter for every 250 grams of flour. Victoria's daughter made cookies using 340 grams of butter for every 400 grams of flour.What will Victoria think of her daughter's cookies?Choose 1 answer:AThey have too much butter.BThey don't have enough butter.CThey have the right amount of butter. Madison was given a large box of 42 chocolates for her birthday. If she eats exactly 5chocolates each day, how many chocolates would Madison have remaining 5 daysafter her birthday? . Does the evidence from your observations support your hypothesis? Next week, our parents are taking us to see a play called The Lion King.underline or quotations marks? i dont understand this at all- Pls help and show workings It due 30 mins Write a paragraph describing the causes and effects of European colonization during the 15th-17th centuries. * PORFAVOR ES PARA HOY!!!!!Tomando como referencia la pelicula "Diarios de la libertad" responde las siguientes preguntas en tu cuaderno y sube las respuestas 1. Cmo era el nombre de cada una de las "tribu" dentro de la institucin?2. Con cual personajes se sienten ms identificados?3. Cual es el personaje que les parece ms admirable?4. Describe qu fue para ti lo que ayud a los estudiantes a poder expresar sus sentimientos y encontrarle un sentido a la vida mas all de las pandillas?5. Escribe un relato contado alguna situacin de tu vida que te marcara (la historia no necesariamente debe ser algo tragico, tambien puede ser una situacin que te llenara de alegra). from americans shifting viws on immigration how do parargraph 37-38 contribute of the devolepement of ideas in the text Who was the greatest enemy of the Susquehannock? Site where the generic code is stored? (b)The image below shows part of the surface of a leaf.0.1 mm x 0.1 mmThe length and width of this piece of leaf surface are both 0.1 mmCalculate the number of stomata per mm of this leaf surface. Despite his opponents arguments, President Franklin D. Roosevelt responded to the Great Depression by Which jobs does an animal's skeletal system do? help pls!! i will give you brainliest QUESTION 18The traditional balance equals the rights of the people versusa. the rights of the state.b. the rights of the government.c. the rights of society.d. the rights of the individual. Pls help, SHOW WORKINGS/ explain Jane drove 693 miles in 11 hours.At the same rate, how long would it take her to drive 411 miles? Look at the table.Cars SoldAnnual Bonus120$1,800130$1,950150$2,250175$2,625What is the annual bonus for a salesperson who sells 55 cars?$150$825$1,500$8,250 Take a moment and think about your public speaking skills, as well as what makes a goodcommunicator, and write down four things that you think would help you the most.Help me please