Answers
Answer:
See detailed solution below
Explanation:
Now, let us solve each question step by step.
1) Given that;
N = amount of radioactive material at time t
No= amount of radioactive material originally present
t = time required for N amount of radioactive material to remain
t1/2= half life of the radioactive material
So,
N/No = (1/2)^t/t1/2
N/60 = (1/2)^22.8/3.8
N/60= (1/2)^6
N/60=1/64
64 N = 60
N = 60/64
N = 0.9 g
2) N/No = (1/2)^t/t1/2
N/8 = (1/2)^103.2/34.4
N/8 = (1/2)^3
N/8 = 1/8
8N = 8
N = 1 L
3) N/No = (1/2)^t/t1/2
50/No = (1/2)^18/6
50/No = (1/2)^3
50/No = 1/8
No = 50 * 8
No = 400 micrograms
4) N/No = (1/2)^t/t1/2
62.5/500 = (1/2)^26/t1/2
0.125 = (1/2)^26/t1/2
Since 0.125 = 1/8
1/8 = (1/2)^26/t1/2
(1/2)^3 = (1/2)^26/t1/2
Hence;
3 = 26/t1/2
t1/2 = 26/3
t1/2 = 8.7 hours
Related Questions
Which 1-mole sample of atoms requires the least energy to form a mole of positive ions? 1) Ca 2) Ge 3)K 4)Ga
Answers
Answer:
K potassium have least ionization energy among these four
Explanation:
Ionization energy values are given in kilo joule per mole
Ca 590
Ge 762
K 419
Ga 579
From above data we can understand stand K has least and Ge has highest ionization energy
In any chemical process, the matter is neither lost nor gained. *
reaction
conservation of matter
covalent bonds
physical change
Answers
In any chemical process, the matter is neither lost nor gained according to conservation of matter. Therefore, the correct option is option B.
What is matter?Matter is any material that has weight and occupies space by having volume in classical physics as well as general chemistry. All common items that can be felt are ultimately constituted of atoms, which are composed of colliding subatomic particles, therefore "matter" typically comprises atoms and everything made up of them, as well as any particles that act as if they both rest weight and volume.
It does not, however, contain massless particles like photons or even other energy phenomena and waves like light or heat. There are numerous states of matter (also known as phases). In any chemical process, the matter is neither lost nor gained according to conservation of matter.
Therefore, the correct option is option B.
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which atmospheric gas is used by plants and given off by animals
Answers
1. How much heat is required to heat 22 grams of Aluminum from 15 °C to 49° C
Answers
Answer:
670.956
Explanation:
You can use this equation to solve for heat :
Q = m * c * ΔT
Q represents the heat
m represents the mass in kilograms
c is the specific heat. For aluminum, it's 897
ΔT is the change in temperature, so, 49 - 15 which is 34
Plug in the numbers and you get this :
Q = 0.022 * 897 * 34
Q = 670.956 Joules
Ed made pancakes from batter, freshly squeezed orange juice, fried eggs, and a strawberry fruit salad. Identify the chemical changes that occur to the food items during breakfast preparation
Answers
Answer:
Warming the batter and frying the eggs.
Explanation:
This is a chemical change as the products have very different property as compared to reactant not only physically but also chemically. Therefore, the reaction that is associated with cooking is combustion reaction.
What is chemical change?
Chemical change is a reaction in which breaking and forming of new bonds take place. One molecule completely converted to totally different molecule. The number of atoms remains same
One famous example of chemical change is the rusting of iron. The color, odor and arrangements of atoms in products are very much different from reactant. Chemical change are mostly irreversible in nature.
Cooking is a chemical change not a physical change. During cooking the reaction that is associated is combustion reaction as the by product is carbon dioxide and water.
Therefore, the reaction that is associated with cooking is combustion reaction.
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Use the periodic to fill in the numbers in the electron configurations shown below.
B: 1s2 2sA2pB
A =
2
B =
1
Na: 1s22sC2pD3sE
Answers
Answer:
B: 1s²2s²2p¹
Na: 1s²2s²2p⁶3s¹
Explanation:
A = 2
B = 1
C = 2
D = 6
E = 1
Hope that helps.
Answer:
B: 1s2 2sA2pB
A = 2
B = 1
Na: 1s22sC2pD3sE
C = 2
D = 6
E = 1
The oxidation # (charge) of an element called "lindenium "Ld is + 1 and the oxidation # (charge) of an element called "mendezine symbol "Mz, is -2. What is the chemical formula for the compound called lindenium mendezide?
Answers
Answer:
Ld₂Mz
General Formulas and Concepts:
Chemistry - Compounds
Valence shellsWriting chemical compoundsBalancing chargesExplanation:
Step 1: Define
"Lindenium" Ld w/ oxidation charge of +1
"Mendezine" Mz w/ oxidation charge of -2
Step 2: Write Compound
To balance out the charges to be neutral (0), we must counter balance the amount of Ld's with Mz's. We need 2 Ld's with 1 Mz to create a compound with a neutral charge:
2Ld¹⁺ + Mz²⁻
2(+1) + (-2) = (+2) + (-2) = 0 (neutral charge)
Therefore, our compound must be Ld₂Mz.
What are 1a 3b and 7a explains on the periodic cable
Answers
Answer:
Explanation:
1a=group 1 elements(H,Li,Na,K....)
3b=group 3 elements (Sc,Y,La....)
7a=group 17 elements (F,Cl,Br,I....)
Test Yourself
1- Which is larger:
a) Million or billion?
b) A part of million or a part of billion?
2- Which is more harmful: concentration of a poisonous substance (lead) in
drinking water to be a part of a billion or a part of a million?
Answers
Answer:
billion is larger \ part if billion
Why does soap work to remove oil? (Note that most oils can be considered non-polar. A soap molecule has one end that is polar and one end that is non-polar.)
Answers
Answer:
Soap breaks up the oil into smaller drops, which can mix with the water.
Explanation:
This works because soap is made up of molecules with two different ends.
The soap molecules works as a surfactant for the water oil interphase. The hydrophobic head of the soap molecules trap the oil and dirt ad remove from the surface.
What are surfactants?Surfactants are chemical substances used to reduce the interfacial tension between substance boundary. Soaps and detergents acts as surfactants which are used to remove the dirt and oil from material surface.
Soap has both polar and non-polar characteristics. The alkaline part in the soap causes it to have a polar head, and because of the electric charge on this head, the soap is hydrophilic. A hydrophilic part of soap is drawn to water and will cling to it.
In this instance, the positive-charged hydrogen atoms of the water's hydrogen atoms match with the polar head of the soap molecule. The other part of soap is a fatty acid tail, which is hydrophobic and can bind with the oil and dirt. The trapped oil molecules are then be removed by water.
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Para preparar 1 kilogramo de arcilla se requieren 400 gramos de agua. Si a nivel del laboratorio solo se cuenta con una probeta y sabemos que la densidad del agua es 1100Kg/m3 ¿Cuántos litros de agua se deben añadir?
Answers
Answer:
0.364 L
Explanation:
Para resolver este problema es necesario expresar la densidad en g/L.
Para hacer esa conversión primero convertimos m³ en L:
1 m³ = 1000 L1100 [tex]\frac{kg}{m^3}* \frac{1m^3}{1000L}[/tex] = 1.1 kg/LY después convertimos kg en g:
1.1 kg/L * [tex]\frac{1000g}{1kg}[/tex]= 1100 g/LFinalmente dividimos la masa deseada (400 g) entre la densidad, para calcular el volumen:
400 g ÷ 1100 g/L = 0.364 LHow many grams of calcium are made up by 2.68 x 1023 atoms?
Answers
Answer:
Mass = 17.8 g
Explanation:
Given data:
Number of atoms of Ca = 2.68 × 10²³
Mass in gram = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.68 × 10²³ atoms × 1 mole /6.022 × 10²³ atoms
0.445 mol
Mass in gram;
Mass = number of moles × molar mass
Mass = 0.445 mol × 40 g/mol
Mass = 17.8 g
how is the strength of an acid affected by the number of hydrogen ions it contains
Answers
Answer:
The greater the number of hydrogen ions, the increase in the acid strength.
Explanation:
Hydrogen ions determine the pH of the acid, greatest number of hydrogen ions give the pH value below 4 hence strong acid, and least number of hydrogen ions give a pH value above 4 but less than 7 hence a weak acid
How many H2O molecules are in 2 mol
Answers
Answer:
A mole of horses would be Avogadro number of horses (a lot actually !). Avogadro number is 6.023 x 10(23). A mole of H (hydrogen) atoms contains 6.023 x 10(23) H atoms. A mole of H2 molecules contains 6.023 x 10(23) H2 molecules or 2 moles of H atoms (since each molecules has 2 atoms).
Explanation:
Answer:
A mole (mol) is the amount of a substance that contains 6.02 × 10 23 representative particles of that substance. The mole is the SI unit for amount of a substance. Just like the dozen and the gross, it is a name that stands for a number. There are therefore 6.02 × 10 23 water molecules in a mole of water molecules.
Explanation:
HELP! ASAP
WILL MARK DOWN BRAINLIEST
Answers
Answer:
SO 4. IS he has small dicke
:D happy to help
Explanation:
A can of cola contains approximately 240 calories. If you consume two cans of cola each day for one week, approximately how many calories did you consume from cola?
Select one:
a. 3,400 calories
b. 70 calories
c. 1,700 calories
d. 480 calories
Answers
You don’t specify whether we round that number or you don’t specify whether we calculate the calories consumed weekly or daily
During photosynthesis what takes place under the leaf
Answers
Answer:
In plants, the process of photosynthesis takes place in the mesophyll of the leaves, inside the chloroplasts. Chloroplasts contain disc-shaped structures called thylakoids, which contain the pigment chlorophyll.
Explanation: Hope this helps
Your explanation should include a claim, evidence, and scientific reasoning based on the data provided and the process of photosynthesis.
Answers
Answer:
yuh 100% true dude
Explanation:
...............
There is a mixture of three gases. We know the total pressure is 2.50 atmosphere and the pressure of the oxygen and the nitrogen in the mixture are 0.52 atmosphere and 0.84 atmosphere. The jar containing the gases has a volume of 25.0 liters and is at a temperature of 32 degrees Celsius. What are the pressure and the number of moles of carbon dioxide in the container?
Answers
Answer:
1.14 atm and 1.139 mol
Explanation:
The total pressure of the container is equal to the sum of the partial pressure of the three gasses:
P = Poxygen + Pnitrogen + Pcarbon dioxide2.50 atm = 0.52 + 0.84 + Pcarbon dioxideNow we solve for the pressure of carbon dioxide:
Pcarbon dioxide = 1.14 atmTo calculate the number of CO₂ moles we use PV=nRT:
P = 1.14 atmV = 25.0 Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 32 °C ⇒ 32 + 273.16 = 305.16 K1.14 atm * 25.0 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 305.16 K
n = 1.139 molhow long does it take to drive a distance of 260 miles at a speed of 65 mph?
Answers
Answer:
4 hours
Explanation:
Calculate: The molecular mass of a molecule is the sum of the masses of each atom in the molecule. The
unit of molecular mass is the universal mass unit (u).
Iron's atomic mass is 55.85 u, carbon's mass is 12.01 u, and oxygen's mass is 16.00 u.
Calculate the molecular mass of carbon dioxide (CO2)
Answers
Answer:
44.01
Explanation:
12.01 + 16.00 + 16.00 = 44.01
How do the particies in a liquid create surface
tension?
Answers
It's been a while since I've taken Chemistry but here's what I know:
There are small, weak bonds that form between water molecules. These bonds make it so liquid molecules (water, in this example) cannot move as freely as a gas, but their bonds aren't nearly as strong as a solid. The bonds are formed when a hydrogen atom is attracted to an oxygen atom (because they have an opposite charge). This bond plus the gas molecules hitting the water causes surface tension.
(Let me know if this is wrong and I hope you have a lovely day!!)
what is love made out of ?
Answers
PLEASE HELP
Electrical devices have been designed to convert electrical energy to other useful
forms of energy. Choose the device which converts electrical energy to kinetic
energy.
Answers
Answer:
B. Fan
Explanation:
The device in the options which converts electrical energy to kinetic
energy is the Fan.
When the fan is plugged to a an electric power source, the electrical energy gets converted to kinetic energy as a result of the movement of the blades in which Kinetic energy is defined as the energy as a result of the motion of a particle or substance.
Tony sets up an experiment inside his classroom. He spaces 5 plants at equal distances along a straight line, with the first plant directly in front of a window and the last plant 10 meters (m) away from the window. He gives them equal access to air and water and then monitors the amount of gas each plant releases.
Which gas is Tony monitoring and what trend is he most likely to see in the data he collects?
He is monitoring oxygen. The amount of gas released should be highest for the plant in the middle and lowest for the plants at the ends.
He is monitoring carbon dioxide. The amount of gas released should be highest for the plant in the middle and lowest for the plants at the ends.
He is monitoring oxygen. The amount of gas released should be highest for the plant closest to the window and lowest for the plant farthest away from the window.
He is monitoring carbon dioxide. The amount of gas released should be highest for the plant closest to the window and lowest for the plant farthest away from the window.
Answers
Answer:
I believe the answer is
"He is monitoring oxygen. The amount of gas released should be highest for the plant closest to the window and lowest for the plant farthest away from the window."
Explanation:
I may be wrong but thats my guess it seems the most accurate
What is the mass of a lead block that has a volume of 30 mL?
O 3.39 grams
O .377 mL
O 265 mL
O 339 grams
Answers
Answer:
d
Explanation:
i think it's d, but I'm not sure. my answer is a little different but maybe i used a different number for the density of lead (11.35g/cc)
5. (10 Points) Write a synthesis reaction where one of the reactants is aluminum.
Include the states of matter for each of the reactants and products.
Answers
Answer:
A reaction in which two or more reactants combine to form only one product is called a synthesis reaction.
Explanation:
Which of the following is a possible compound formed from Ca2+ and NO3-1?
F Ca2NO3
G Ca(NO3)2
H Ca3NO2
J CaNO
Answers
Answer:
Ca(NO3)2
.................
Ca(NO3)2 is a possible compound formed from Ca²+ and NO3-¹.
Ions, which are charged atoms of elements come together to form ionic compounds. A positively charged ion called cation reacts with a negatively charged ion called anion to form a neutral ionic compound i.e. compound with a charge of 0. In this question, cation Ca²+ reacts with anion NO3-. The ionic compound formed must have a net charge of 0. This can only happen if 2 moles of NO3- and 1 mole of Ca²+ is present in the compound. The resulting ionic compound can be chemically represented as Ca(NO3)2. Therefore, Ca(NO3)2 is a possible compound formed from Ca²+ and NO3-¹.Learn more at: https://brainly.com/question/11148793?referrer=searchResults
Choose two different particles found in the air. Explain how they are different and how they are the same
Answers
Answer:
Dust and smoke.
Explanation:
Dust and smoke are two different particles present in the air. Dust and smoke are different from one another due to their origin. Smoke formed from burning of materials while dust refers to the soil particles lifted by the wind due to their light weight. Dust and smoke are similar to each other due to their small in size, infinite number means uncountable and light weight.
Air is a mixture of gases and consists of dust particles and water vapor. It consists of small to very large size of particles. Some of them include dust pollen, soot, and liquid droplets.
Dust and soot particles of the air are different as the soot is a fine black particle of carbon and tar. It is made by the incomplete combustion of air. While dust is fine dry particles of matter.Hence they both differ.
Learn more about the two different particles found in the air.
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22.
An example of amphoteric oxide is
A. Al2O3.
B. CaO.
C. Cuo.
D. SiO2.
E. K20.
Fu** please help
Answers
Answer:
A (option) .............
Answer:
Al2O3
Explanation:
ZnO,Al2O3,PbO2 are some of the amphoteric oxides
Amphoteric oxides are metal oxides that can react with both acids and bases,so Aluminum oxide can react with both HCl and Sodium hydroxide which is a base