Answer:
Half-life = 2.7 days
Explanation:
The radioactive decay of an isotope follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] could be taken as the amount of A after t time, k is decay constant, [A]₀ initial amount of A.
Replacing to solve k:
Ln[3.125g] = -k*13.5days + ln[100g]
-3.465736 = -k*13.5days
k = 0.2567days⁻¹
Half-life is:
half-life = ln2 / k
Half-life = 2.7 days
Explain the method to decrease friction?
Answer:
having a smooth or lubricated surface may help decrease friction.
Explanation:
2Cr^3 + 3Zn(s) -> 2Cr(s) + 3Zn^2 + (aq) which reactant is reduced and which is oxidicided
Answer:
Cr is oxidised
and
Zn is reduced
[ Reduced reactant ] :
Cr^( + 3 ) + 3 e^( - 1 ) ===》 Cr^( 0 )
_____________________________
[ Oxidicided reactant ] :
Zn^(0) ===》Zn^( + 2 ) + 2 e^( - 1 )
When temperature drops, (for example from 20 degrees celsius to 10 degrees celsius)
a.) energy increases
b.) particles move slower
c.) particles collide more often
d.) pressure increases
Answer:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
Explanation:
In the Celsius scale each degree is one part of 100 degrees. This is because in this scale the difference between boiling and freezing temperatures of water is 100 ° - 0 ° = 100 °, so one degree Celsius is one part of 100.
In the Farhenheit scale, each degree is one part of 180 degrees. This is because in this scale the difference between the boiling and freezing temperatures are 212 ° - 32 ° = 180°, so one degree Fahrenheti is one part of 180.
That means that 1 °C is a larger amount than 1 °C, so 20°C is a larger amount than 20°F.
Conclusion: 20 degree change represents a larger change in Celsius scale.
How many formula units are there in 14.50 moles of any compound?
___X 10^___formula units
Answer:
8.73 × 10²⁴ formula units
Explanation:
To calculate the number of formula units a substance contain, we multiply the number of moles by Avagadro number (6.02 × 10²³)
number of formula units = 14.50 moles × 6.02 × 10²³
= 87.29 × 10²³
= 8.73 × 10²⁴ formula units.
0.444 mol C2H5OH= how many molecules
Explanation:
hope it make sense to u :)
What element is produced when Mercury - 204 undergoes alpha decay?
Answer:
bismuth
Explanation:
i think if not i am so sorry
Does the excess reactant get used up completely in a reaction??
Answer:
In a chemical reaction, reactants that are not used up when the reaction is finished are called excess reagents. The reagent that is completely used up or reacted is called the limiting reagent, because its quantity limits the amount of products formed.
Explanation:
is A tomato smells rotten a chemical
reaction
Answer:
yup
Explanation:
because chemical change took place
the reaction cant be reversible
If a piece of pure gold jewelers weighs 11.81 grams, how many atoms is it made of?
Answer:30.573 Billion atoms are in one gram
Explanation:
What is the rate of diffusion of NO gas to CO gas?
Answer:
0.97
Explanation:
Let R₁ represent the rate of diffusion of NO.
Let R₂ represent the rate of diffusion of CO.
Molar mass of NO (M₁) = 14 + 16 = 30 g/mol
Molar mass of CO (M₂) = 12 + 16 = 28 g/mol
Thus, the rate of NO to CO can be obtained as follow:
R₁ /R₂ = √(M₂/M₁)
R₁ /R₂ = √(28/30)
R₁ /R₂ = √(28/30)
R₁ /R₂ = 0.97
R₁ : R₂ = 0.97
NO : CO = 0.97
Therefore, the rate of diffusion of NO to CO is 0.97
Someone please help me
Answer:reflection
Explanation:
Gas particles that are at low temperature and high pressure and are close to changing phases are considered:
a)Real Gases
b)Ideal Gases
c)Both Ideal and Real Gases
Sodium chloride is produced from its elements through a synthesis reaction. What mass of each reactant would be required to produce 22.0 mol of sodium chloride? sodium
Answer:
506.0 g sodium and 778.8 g chlorine gas
Explanation:
The elements from which sodium chloride (NaCl) is composed are sodium (Na) and chlorine (Cl). Thus, the chemical equation for the production of sodium chloride (NaCl) from sodium (Na) and chlorine gas (Cl₂) is the following:
2Na(s) + Cl₂(g) → 2NaCl(s)
According to the balanced equation, 2 moles of NaCl are produced from 2 moles of Na(s) and 1 mol of Cl₂. To produce 22.0 mol of NaCl, we need:
22.0 mol NaCl x 2 mol Na(s)/2 mol NaCl = 22.0 mol Na(s)
22.0 mol NaCl x 1 mol Cl₂/2 mol NaCl = 11.0 mol Cl₂
Now, we convert the moles of each reactant to grams with the molar mass (MM) of the compound:
MM(Na) = 23 g/mol
22.0 mol Na x 23 g/mol = 506.0 g Na(s)
MM(Cl₂) = 35.4 g/mol x 2 = 70.8 g/mol
11.0 mol Cl₂ x 70.8 g/mol = 778.8 g Cl₂
Therefore, it is required a mass of 506.0 grams of Na(s) and a mass of 778.8 grams of Cl₂ to produce 22.0 mol of NaCl.
Another term for natural radioactive decay into another element is
Answer:
The process of unstable (or radioactive) atoms becomes stable by emitting radiation. This event over time is called radioactive decay. Alpha decay results in the loss of two protons and two neutrons from the nucleus
Answer:
radioactive disintegration
Explanation:
How many grams of LiF are needed to make 87 g LiF solution into a
34.5% solution?
solution?
answer options:
30 g LIF
0.01 g LIF
45.8 g LIF
0.02 g LIF
Answer: 30 g LiF
Explanation:
Which of the following is a correct statement about water? (3 points)
Hydrogen bonding causes water to be strongly cohesive.
Hydrogen bonding causes water to have a low surface tension.
Water is a universal solvent because polar and nonpolar solutes can dissolve in it.
Water is less dense as a liquid than as a solid because of changes in bond structure.
Answer:
A: Hydrogen bonding causes water to be strongly cohesive.
Explanation:
Water has a high surafce tension. Hence droplets of water
Water cannot dissolve non polar substances like oil; only polar
Water is actually less dense in solid form :)
Hydrogen bonding causes water to be strongly cohesive.
This sticking together of like substances is called cohesion. Depending on how attracted molecules of the same substance are to one another, the substance will be more or less cohesive. Hydrogen bonds cause water to be exceptionally attracted to each other. Therefore, water is very cohesive.
Cohesion
Cohesion, also called cohesive attraction or cohesive force, is the action or property of like molecules sticking together, being mutually attractive. It is an intrinsic property of a substance that is caused by the shape and structure of its molecules, which makes the distribution of surrounding electrons irregular when molecules get close to one another, creating an electrical attraction that can maintain a microscopic structure such as a water drop. In other words, cohesion allows for surface tension, creating a "solid-like" state upon which light-weight or low-density materials can be placed.
Learn more about Cohesion
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The chemical equation for zinc in hydrochloric acid is: Zn + HCI = ZnCl2 + H2
Does the above equation demonstrate the law of conservation of mass as it is currently written? Explain why or why not.
Answer: No it does not
Explanation:
The law of conservation of mass states that mass is neither created nor destroyed and in this equation you start with 1 molecule of Cl and 1 of H, but on the reactants side you end up with 2 of each. To make it follow the law of conservation of mass you would have to balance the equation
Mole ratios used for conversions come from?
How much energy required to raise the temperature of lead by the same degrees.
Answer:
If a one kilogram block of lead absorbs 2,000 J of energy then the temperature rise will be larger. If 1,000 J of heat is absorbed by a 2 kg block of lead then the temperature of the block doesn't rise as much since the energy is shared between more particles.
Explanation:
Please help me I will give brainliest to the first correct answer
Answer:
OPTIC B) HEPT-HOPE IT IS HELPFUL
Examine the food chain below: In this specific food chain, the _______ eats plants for food. A. caterpillar B. sunshine C. bobcat D. leaf
why metal in the middle of metal activity series can't be obtained by heating ors in air
Answer:
See Explanation
Explanation:
The way by which a metal is obtained from its ore is determined by the chemical reactivity of the metal.
Metals that are highly reactive are chiefly obtained by electrolysis of the metal salt. These metals are found high up in the metal activity series.
Metals that are at the middle of the series are moderately reactive and are obtained by electrolysis or by reduction since they still form ionic salts.
Metals that are far lower in the series can only be obtained by heating them in air because they are mostly unreactive.
Hence, moderately reactive metals at the middle of the series are not obtained by roasting in air.
2. How did the Activator affect the mixture?
Answer:
Activator effects a mixture if you put to much of the activator your using into a product or thing you are using.
Explanation:
For ex.
If you poor to much activator into slime it will make the slime hard and very wet it will ruin your slime completely so you will have to do it just right but start off pouring it slowly and mix and then more if it needs more.
the tissue which continually forms new cells in plants
Answer:
Meristematic Tissues. Tissues where cells are constantly dividing are called meristems or meristematic tissues. These regions produce new cells.
Explanation:
thank me later
An ideal gas is contained in a cylinder with a volume of 5.0x102 mL at a temperature of 30°C and a pressure of 710. Torr. The gas is then compressed to a volume of 25 mL, and the temperature is raised to 820° C. What is the new pressure of the gas?
Answer:
51207 torr is the new pressure of the gas
Explanation:
We can solve this question using combined gas law that states:
P1V1T2 = P2V2T1
Where P is pressure, V volume and T absolute temperature of 1, initial state and 2, final state of the gas
Computing the values of the problem:
P1 = 710torr
V1 = 5.0x10²mL
T1 = 273.15 + 30°C = 303.15K
P2 = ?
V2 = 25mL
T2 = 273.15 + 820°C = 1093.15K
Replacing:
710torr*5.0x10²mL*1093.15K = P2*25mL*303.15K
3.881x10⁸torr*mL*K = P2 * 7.579x10³mL*K
P2 = 51207 torr is the new pressure of the gas
Balance the following equation:
Cr + __02 +_Cr203
Answer:
4Cr + __302 -->_2Cr203.....
Balance the following equation: _H2+ __02 - __ H20
Answer:
2
H
2
+
O
2
=
2
H
2
O
Explanation:
From the original equation, you first need to write each component separately.
H
2
+
O
2
=
H
2
O
Left side: H = 2 ; O = 2 (number based on the subscript)
Right side: H = 2 ; O = 1 (number based on the subscripts; no subscript means that the element is just 1)
Notice that the number of H is already balance but the number of O is not. In order to balance the O, you need to multiply the element by 2, but you CANNOT do this by simply changing the subscript.
Hence,
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
Now, notice that the number of O is now balance (both are 2) but the number of H is not (since
H
2
O
is a substance and not an element, you need to multiply everything by 2). So, what to do?
You also multiply the left side H by 2. Hence,
2
H
2
+
O
2
=
2
H
2
O
Left side: H = 2 x 2 = 4 ; O = 2
Right side: H = 2 x 2 = 4 ; O = 1 x 2 = 2
The equation is now balanced.
The interaction of the skeletal and muscular systems to create movement and locomotion is regulated by which organ system?
Answer:
The muscoloskeletal system
Explanation:
The musculoskeletal system is made up of the body's bones (the skeleton), muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together. Its primary functions include supporting the body, allowing motion, and protecting vital organs.
how many moles are in 0.14g of Nitrogen, N2?
Answer:
0.01 moles
Explanation:
14 g contains 1 mole
0.14g contains> (0.14*1)/14
= 0.01 moles
What is diffusion? How does the motion of gas molecules explain how a gas diffuses throughout a room?
Answer:
Diffusion in gases
Diffusion is driven by differences in concentration. When chemical substances such as perfume are let loose in a room, their particles mix with the particles of air. The particles of smelly gas are free to move quickly in all directions
Explanation:
hope this helps