Answer:
after 4 half-lives, 125g is left
Explanation:
The half-life of a radioactive substance is the time it takes for the substance to decay by half its original mass.
In this example, we are asked to find the remaining mass after four half-lives.
What we will simply do is to reduce the starting mass by half, after each half-life decay. this is done as follows:
1st half-life decay: starting mass 2000g
final mass = 2000g ÷ 2 = 1000g
2nd half-life decay: starting mass = 1000g
final mass = 1000 ÷ 2 = 500
3rd half-life decay: starting mass = 500
final mass = 500 ÷ 2 = 250g
4th half-life decay: starting mass = 250g
final mass = 250 ÷ 2 = 125g
∴ after 4 half lives, 125g is left
For the reaction
? P4+? S8 - ? P4S10
what is the maximum amount of P4S10 which
could be formed from 15.29 g of P4 and 17.66 g
of Sg?
Answer in units of g.
Please hurry it’s due today and include the steps if you can
Se ard 25g de magneziu de puritate 90%. Ce volum de oxigen se consumă și câti moli dioxid de magneziu se formează
Answer:
10.5 dm3 O2
0.94 moles de MgO
Explanation:
La pregunta dice explícitamente que el magnesio es puro en un 90%.
Por lo tanto, masa de magnesio puro = 90/100 * 25G = 22,5 g
Número de moles de Mg = 22,5g / 24g/mol = 0,94 moles de Mg
La ecuación de reacción es;
2Mg (s) + O2 (g) ------> 2MgO (s)
Si 2 moles de Mg reaccionan con 1 moles de O2
0.94 moles de Mg reacciona con 0.94 * 1/2 = 0.47 moles de O2
Si 1 mol de O2 ocupa 22,4 dm3
0.47 moles de O2 ocupan 0.47 * 22.4 / 1 = 10.5 dm3
También;
2 moles de Mg producen 2 moles de MgO
Entonces, 0.94 moles de Mg producen 0.94 moles de MgO
Why is a pyramid shape used to represent the energy in an Ecosystem?
Answer:
An energy pyramid shows the flow of energy at each trophic level in an ecosystem. A pyramid shape is used because energy is lost at each trophic level when organisms use it up.
Explanation:
What happens when a base dissolves?
O A. It increases the concentration of OH in solution.
O B. It increases the concentration of Hi in solution.
O C. It is no longer dangerous.
O D. It adds oxygen to the solution.
Answer:
A. It increases the concentration of OH in solution.
Explanation:
Answer:
B. It increases the concentration of Hi in solution.
Explanation:
A.p.e.x
Please I need this help me
Answer:
first of all is that really chemistry
What is the relationship between atoms and mass?
Answer:
Explanation:
A property closely related to an atom's mass number is its atomic mass. The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu.
A protein is a polymer that is made of
Answer:
A protein is a polymer that is made of amino acids.
How can scientists control the flammability of a substance?
Answer: This is simple, if it has a high flammability, and you light it on fire, then that would be a chemical change.
Explanation:
May i have brainliest please and don't forget to drop a heart
Which of the following correctly describes the difference (on average) between an electron in a 2s orbital and an electron in a 3s orbital?
Answer:
C: electrons is the 3s orbital are higher than those in the 2s orbital
Explanation:
Looking at the options, the correct one is that the electrons in the 3s orbital will possess more energy than those in the 2s orbital. This is because the the 2s orbitals will be filled with electrons first before the 3s orbital.
Also from basics we know that the energy of an orbital increases as the quantum number increases.
2. How much force, in g cm / s2 , is exerted by a golf ball described in problem 1 striking a tree while accelerating at 20 cm / s2 ? Show how you can solve this problem without knowing that F = m a. Explain your solution.
Answer:
F = 1000 g cm/s²
Explanation:
Let the weight of 1 ball is 50 gram
Acceleration, a = 20 cm/s²
We need to find the force exerted by a golf ball. We know that,
F = ma
So,
F = 50 g × 20 cm/s²
F = 1000 g cm/s²
So, the required force is 1000 g cm/s².
A tank for storing liquid as a base of area 1.5 meters square. What is the pressure on the base of the tank when it contains water weighting 4500n
Answer:
3000 Nm^2
Explanation:
We must remember that pressure is defined as force per unit area.
We have been given the following information in the question;
Area of the tank= 1.5 m^2
Weight of water in the tank = 4500N
And;
P = F/A
F= force
A = area
P = 4500 N/1.5m^2
P= 3000 Nm^2
What will most likely cause a sudden wind to start blowing?
Answer:
wind is just high and low pressure of air, when a high pressure comes and crashes into a low pressure air pocket than it can form a wind storm.
Explanation:
The Uneven heating of the Earth's surface. Earth's rotation and unequal heating of the Earth's surface. air pressure towards regions of lower air pressure. ... air moving from areas of high pressure to areas of low pressure.
This is what will most likely cause a sudden wind to start blowing.
Which organism in the food chain is
responsible for transforming radiant
energy into chemical energy?
Grass->Prairie Dog -> Coyote -> Soil Bacteria
Answer:
The organism in the food chain responsible for transforming radiant energy into chemical energy is;
Grass
Explanation:
Radiant energy is the energy present in electromagnetic waves which carry photons that may be considered as energy packets. It is an energy present in the Sunlight, which is an electromagnetic waves, and it is the energy in the electromagnetic waves that plants convert to chemical energy for food in the process known as photosynthesis as follows;
6CO₂ + H₂O + Radiant energy → C₆H₁₂O₆ + 6O₂
Therefore the organism in the food chain responsible for transforming radiant energy into chemical energy is the plant, grass
In a 63.17 g sample of SOs, how many grams are sulfur?
Answer:
25.30 gram
Explanation:
No of moles = given mass / molar mass
No of moles = 63.17/80.06
0.7890 moles
Mass of sulphar = no of moles× molar mass of sulphar
Mass of sulphur = 0.7890×32.065
25.30 gram
Marie Curie was discriminated against because she was a woman. Do you feel that there are still barriers to women entering careers in science these days2. Explain your answer.
Answer:
yes I do I feel like people think that people's are thinking that men are stronger then women in someone situations
Answer:
yes
Explanation
i would say yes because many woman and girls struggle to get jobs because of their record,hair,skin color,and past.
Please help due today!
for the first one it is B OR THE SECOND OPTION
The light energy captured during photosynthesis is stored as
water.
sugar.
carbon dioxide.
electrons.
Answer:
Sugar
Explanation:
This is because water and carbon dioxide are required during photosynthesis. Oxygen along with glucose, that is a type of sugar is produced. The oxygen is diffused out in to the air, while the sugars are stored in the leaf thus light energy captured during photosynthesis is stored as 'sugar'
What are the four ions formed when sodium chloride undergoes electrolysis?
Answer: The four ions formed are [tex]H^+[/tex] , [tex]OH^-[/tex] , [tex]Na^+[/tex] and [tex]Cl^-[/tex]
Explanation:
Electrolysis is the process where electricity is used to drive chemical reactions.
In the electrolysis of aqueous solution of sodium chloride, hydrogen gas produces at the cathode which is a negative electrode and chlorine gas produces as the anode which is a positive electrode and the sodium hydroxide remains dissolved in the solution.
The reactions will be :
[tex]NaCl\rightarrow Na^++Cl^-[/tex]
[tex]H_2O\rightarrow H^++OH^-[/tex]
Hence, electrolysis of an aqueous solution of sodium chloride lead to the formation of four ions,[tex]H^+[/tex] , [tex]OH^-[/tex] , [tex]Na^+[/tex] and [tex]Cl^-[/tex]
The last electron in an atom of oxygen is added to a ___ orbital.
a. 2p
b. 1p
c. 3p
d. 2s
Answer:
A
Explanation:
If 11.87 grams of sand (SiO2) were contained in the mixture, how many atoms of oxygen were in the mixture?
Answer:
2.38x10²³ atoms oxygen
Explanation:
To solve this question we need to convert the mass of sand to moles using its molar mass (Molar mass SiO₂ = 60.08g/mol). Twice these moles are the moles of Oxygen and using Avogadro's number we can find the amount of atoms of Oxygen in the mixture:
Moles SiO₂:
11.87g * (1mol / 60.08g) = 0.1976moles SiO₂
Moles Oxygen:
0.1976moles SiO₂* 2 = 0.3951moles oxygen
Atoms oxygen:
0.3951moles oxygen * (6.022x10²³atoms / 1mol O₂) =
2.38x10²³ atoms oxygenWhen white light passes through a prism, what can be discovered?
A)
White light is made invisible by passing through prisms.
B)
White light is made brighter by passing through prisms.
White light is made of a spectrum of various colors.
D)
White light gets hotter when it passes through prisms.
Answer:
White light is made of a spectrum of various colors.
Explanation:
As light passes through a prism, it is bent, or refracted, by the angles and plane faces of the prism and each wavelength of light is refracted by a slightly different amount. ... As a result, all of the colors in the white light of the sun separate into the individual bands of color characteristic of a rainbow.
AgNO3 (aq) +
Cu(s) —
Cu(NO3)2 (aq) +
| Ag(s)
What is the integer?
Answer:
2
Explanation:
2AgNO3 + Cu -----> Cu(NO3)2. + 2Ag
what is the formula and give the name of the compound formed by following ions: hydrogen, and nitrite. (hydrogen : H, group 1)
Explanation:
Hydrogen = H
Nitrite = NO₂⁻
The compound formed by Hydrogen and Nitrite is;
Name = Nitrous Acid
Formular = HNO₂
Determine el número de moles presentes en una esfera de titaniode 0.5 cm de radio, sabiendo que la densidad del titanio es de 4507kg/m³. =433
Answer:
0.0493 moles de Titanio
Explanation:
Primero, debemos hallar el volumen de la esfera. Usando la densidad podemos hallar la masa de titanio y usando la masa atómica encontraremos las moles de titanio:
Volumen de la esfera:
Volumen esfera = 4/3π * Radio³
Volumen = 0.5236cm³
En m³ (1m³ = 1x10⁶cm³):
0.5236cm³ * (1m³ / 1x10⁶cm³) = 5.36x10⁻⁷m³
Masa en gramos:
5.36x10⁻⁷m³ * (4507kg / m³) = 2.36x10⁻³kg * (1000g / 1kg) = 2.36g de Titanio
Moles -Masa molar Ti: 47.867g/mol-:
2.36g de Titanio * (1mol / 47.867g) =
0.0493 moles de Titaniowhen do you consider that a typhoon will enter or effect the country
Answer:
sorry I don't understand this subject sorry
Explanation:
What Classification type star this?
Explanation:
The Sun is a as a G2V type star, a yellow dwarf and a main sequence star. Stars are classified by their spectra (the elements that they absorb) and their temperature.
whish this helped!
The formula of methane is CH4. The symbols for the two elements in methane are C and H. Give the names of these two elements.
Answer:
Carbon and Hydrogen
Explanation:
So the C stands for Carbon and H is for Hydrogen. Methane (CH4) is made up of one atom of Carbon and 4 atoms of Hydrogen.
Hope this helps
What are the end products of anaerobic respiration in yeast cell ?
Answer:
glucose ethanol and co2
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Answer:
In anaerobic respiration yeast breaks down glucose, forming ethanol and carbon dioxide as its waste products. When the glucose is nearly used up, and provided that oxygen is present, yeast uses the ethanol as a respiratory substrate to produce carbon dioxide and water in aerobic respiration.
Explanation:
Hope it is helpful....
What provides the energy to set the water cycle in motion?
Nothing, the water cycle does not need energy.
Clouds
Sun
Water.
Which of the following explains this observation?
A. Sound has longer wavelengths than light
B. Light has a greater mass than sound
C. Light travels faster than sound
D. Sound and light travel at the same speed