Answer:
Kr-73 = 23.625 sec
Kr-74 = 10.0625 minutes (603.75 seconds)
Kr-76 = 12.95 hours (777 minutes)
Kr-81 = 1.8375 * 10^6 years
Explanation:
What you do is multiply each of those amounts by 7/8.
27 * 7/8 = 189/8 = 23.625
23/2 * 7/8 = 161/16 = 10.0625
74/5 * 7/8 = 518/40 = 259/20 = 12.95
210000 * 7/8 = 1470000/8 = 183750 = 1.8375 * 10^6
is methane used as fule
gas true or false
Answer:
its true methane is used as a fuel gas
Explanation:
balance the following skeleton equations Mg+02---->MgO
Answer: [tex]2Mg+O_2\rightarrow 2MgO[/tex]
Explanation:
Skeletal equations are defined as the equations in which formula are used to indicate the chemicals that are involved in a chemical reaction.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Thus the balanced chemical equation will be :
[tex]2Mg+O_2\rightarrow 2MgO[/tex]
At which point is kinetic energy greatest
Answer:
x is wen
Explanation:
Answer:
I would say at point ''X''
PLEASEEE HELP me on CHEMISTRY!! Will give brainliest!
Two students plan and carry out an investigation to determine if ionic or covalent bonds have stronger intermolecular forces. They check the following data.
a. identify the type of intramolecular bonds that are involved.
b. Which substance will have the stronger intermolecular forces?
c. Which properties allow you to predict the strength of the intermolecular forces?
Answer:
A Glucose C6H12O6 is a covalent compound while NaCl sodium chloride is a ionic compound.
B Stronger molecular forces are present in NaCl because ionic bond is stronger than covalent bond.
C melting point allow us to predict the strength of intermolecular forces
High melting point stronger molecular forces and vice versa.
Explanation:
Need help fast please!
Find the mass of 4.56 mols of LaPO4
Answer:
Mass = 1080.26 g
Explanation:
Given data:
Number of moles of LaPO₄ = 4.56mol
Mass in gram = ?
Solution:
Formula:
Number of moles = mass/molar mass
Molar mass of LaPO₄ = 236.9 g/mol
by putting values,
4.56 mol = mass/ 236.9 g/mol
Mass = 4.56 mol × 236.9 g/mol
Mass = 1080.26 g
The temperature of 25 g of water was raised from 10 oC to 60 oC. How many joules of heat was necessary to accomplish this?
Answer:
Hope this helps!
Explanation:
ygyjhu went to the store and bumped into afghsiugshjkds
Answer:
well dont hurt yourself
Explanation:
its not very good to
The reaction energy type that has a negative value at the end of the reaction is called: a Barothermic b Exothermic c Endothermic d Isothermic
Answer:
b) Exothermic
Explanation:
Exothermic reaction:
The type of reactions in which energy is released are called exothermic reactions.
In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.
For example:
Chemical equation:
C + O₂ → CO₂
ΔH = -393 Kj/mol
it can be written as,
C + O₂ → CO₂ + 393 Kj/mol
Which of the following is true about nuclear fusion
a) it occurs in the sun
b) a heavy atom is split
c) it can be controlled easily
d) an electron is lost by the atom
Answer:
i would assume that it would be (a)
Explanation:
The Sun generates its energy by nuclear fusion
NUCLEAR FISSION is when the heavy atom is split
fusion energy is scientifically feasible. Plasma conditions that are very close to those required in a fusion reactor are now routinely reached in experiments
mass gets lost is nuclear fusion
so (a) is the most accurate
Answer:
it occurs in the sun
Explanation:
just took the test so its A. GL!
if hydrochloride tablets and eno combine what will the reaction
answer is attached in the image below
Answer:
Hydrochloric Acid
Explanation:
Based only on the distance between the valence electron and the nucleus, which atom has a stronger attraction between its nucleus and its valence electrons? How do you know? Please explain in at least 2 sentences.
lithium and sodium
Answer:
Lithium
Explanation:
Although sodium may seem like a viable answer because it has more protons (and thus a greater attractive force) in its nucleus, we need to take into account what "valence electrons" means. Valence electrons are, simply, electrons that are on the outermost electron shell of an atom. Sodium has an additional shell of electrons compared to lithium that are far away from the nucleus. Thus, lithium, which has valence electrons closer to its nucleus, would have a stronger attraction between its nucleus and its valence electrons.
what is the specific heat of the following materials:
aluminum
water
rubbing alcohol
cooking oil
Answer:the sun
Explanation:leqjs
Let's look it up
Aluminium:-
0.89 J/kg°CWater:-
4.186J/g°CAlcohol:-
0.588cal/g°CCooking oil:-
1.67Kj/kg°CWhich formula represents a polar molecule? 1. O2 2. CO2 3. NH3 4. CH4
Answer:
NH3.
Explanation:
You can draw Lewis diagrams to answer this question and what distinguishes a polar from a nonpolar molecule: A nonpolar molecule must be symmetric and have no lone pairs on its central atom. The only one that fits the criteria necessary to be a polar molecule is NH3.
The chemical formula which represents a polar molecule is NH₃ as there is charge separation in the molecule.
What is chemical formula ?Chemical formula is a way of representing the number of atoms present in a compound or molecule.It is written with the help of symbols of elements. It also makes use of brackets and subscripts.
Subscripts are used to denote number of atoms of each element and brackets indicate presence of group of atoms. Chemical formula does not contain words. Chemical formula in the simplest form is called empirical formula.
It is not the same as structural formula and does not have any information regarding structure.It does not provide any information regarding structure of molecule as obtained in structural formula.
There are four types of chemical formula:
1)empirical formula
2) structural formula
3)condensed formula
4)molecular formula
Learn more about chemical formula,here:
https://brainly.com/question/29031056
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Copper carbonate (CuCO3) reacts with hydrochloric acid (HCl) according to this equation:
CuCO3(s) + 2HCl(aq) → CuCl2(aq) + H2O(l) + CO2(g).
Which statement correctly describes the substances in this reaction?
A.
Exactly one product and two reactants are either liquid or dissolved in water.
B.
Exactly one of the reactants is in a water-based solution, but none of the products are.
C.
The reactants include both a liquid and a gas.
D.
Exactly one reactant is a solid, and exactly one product is a gas.
E.
The products include a solid, a liquid, and a gas.
Answer:
d
Explanation:
plato
Answer:
d
Explanation:
When a pendulum swings, at which point is kinetic
energy highest:
Answer:
3
Explanation:
Which of the following have metallic bonding? 1. Magnesium chloride 2. Hydrogen chloride. 3. Magnesium. 4. Chlorine
Explanation:
Magnesium chloride has Ionic bonding.
Hydrogen chloride has Covalent bonding.
Chlorine has Covalent bonding.
Only Magnesium has metallic bonding (3).
Is NaHCO3 a compound? Explain pls!
Answer:
Yes it is
Explanation: because it is composed of identical molecules consisting of atoms of two or more chemical elements.
hope it helps <3
guys please help me i really need help! pls and thank you!
Answer:
Hydrogen
Explanation:
Convert 12.5 km/L to mi/gal.
Answer:
29.40182
Explanation:
answer with correct significant figures (*no scientific notation): 847.3219 x 34.6 x 1.4560 =
Answer:
42686.04375
Explanation:
Multiply 847.3219 by 34.6 to get 29317.33774, then multiply this answer by 1.4560 to get the final answer which is 4286.04375.
Please help correct answers only please
Answer:
Empirical formula is C₅H₁₂O
Molecular formula = C₅H₁₂O
Explanation:
Given data:
Percentage of hydrogen =13.75%
Percentage of carbon = 68.11%
Percentage of oxygen = 18.15%
Empirical formula = ?
Solution:
Number of gram atoms of H = 13.75 / 1.01 = 13.6
Number of gram atoms of O = 18.15 / 16 = 1.13
Number of gram atoms of C = 68.11 / 12 = 5.68
Atomic ratio:
C : H : O
5.68/1.13 : 13.6/1.13 : 1.13/1.13
5 : 12 : 1
C : H : O = 5 : 12 : 1
Empirical formula is C₅H₁₂O.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass :
5×12 + 12×1.01 + 16×1 = 88.12 g/mol
n = 88.17/ 88.12
n = 1
Molecular formula = n (empirical formula)
Molecular formula = 1 (C₅H₁₂O)
Molecular formula = C₅H₁₂O
What is responsible for the blue sky?
Answer:
sun shine
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time
Answer:
Sunlight
Explanation:
Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. Blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. ... Also, the surface of Earth has reflected and scattered the light.
A wave on a lake has a wavelength of 5.0 M and a Frequency of 4 Hz. What is the speed of the wave in m/s?
Answer:
The appropriate speed will be "20 m/s".
Explanation:
The given values are:
Wavelength,
λ = 5.0 M
Frequency,
f = 4 Hz
Now,
The speed of the wave will be:
⇒ [tex]V=f\times \lambda[/tex]
On putting the values, we get
⇒ [tex]=4\times 5.0[/tex]
⇒ [tex]=20 \ m/s[/tex]
The reaction of magnesium chloride with silver nitrate gives a precipitate of silver chloride.
MgCl2(aq) + 2AgNO3(aq) + Mg(NO3)2(aq) + 2AgCl(s)
A solution containing 0.001 mol of magnesium chloride reacts with excess silver nitrate.
What is the mass of the precipitate formed?
[Molar mass/gmol-': AgCl = 143.4]
A 0.0729
B 0.1439
C 0.287g
D 0.574g
(Total for Question 5 = 1 mark)
Answer:
Mass = 0.287 g
Explanation:
Given data:
Number of moles of MgCl₂ = 0.001 mol
Mass of precipitate formed (AgCl) = ?
Solution:
Chemical equation:
MgCl₂(aq) + 2AgNO₃(aq) → Mg(NO₃)₂(aq) + 2AgCl (s)
now we will compare the moles of MgCl₂ and AgCl.
MgCl₂ : AgCl
1 : 2
0.001 : 2/1×0.001 = 0.002
Mass of AgCl:
Mass = number of moles × molar mass
Mass = 0.002 mol × 143.4 g/mol
Mass = 0.287 g
What is the energy required to go from a solid to a liquid called?
A. The latent heat of fusion
B. The thermal energy of a substance
C. The latent heat of vaporization
D. The specific heat capacity
Answer:
enthalpy of fusion also called heat of fusion
The number of molecules in 48.0 grams of oxygen gas (O2) is...
O 6.02 x 1023
O 1.81 x 1024
O 1.20 x 1024
9.03 x 1023
Answer:
9.033 × 10²³ molecules
Explanation:
Given data:
Mass of oxygen = 48.0 g
Number of molecules = ?
Solution:
Number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 48.0 g/ 32 g/mol
Number of moles = 1.5 mol
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 molecules
1.5 mol × 6.022 × 10²³ molecules / 1mol
9.033 × 10²³ molecules
GIVING BRAINLEST TO WHOEVER HELPS ME AND GETS THE RIGHT ANSWER.
What is the energy source that powers plate movements ?
A. Magma and lava
B. Earth’s magnetic field
C. The sun
D. Earths not interior
Compare and contrast a thermodynamically stable compound and a kinetically stable compound at room temperature with respect to overall energy change, spontaneity with which decomposition occurs, and reaction rate.
Answer:
"im different"
Explanation:
Wut is answer pls???
Answer:
7 no ans is C
8 no ans use of magnet .I am not sure
When 1000 C of charge is passed through CuSO4 solution, x g of copper is deposited. How much charge should be passed through the solution to deposit 5x g of copper?
Number of charge = 5018 C
Further explanationGiven
1000 C of charge for x grams of copper
Required
Number of charge
Solution
Faraday's Law :
[tex]\tt W=\dfrac{e.i.t}{96500}\\\\W=\dfrac{e.Q}{96500}[/tex]
For 1000 C, W = x grams
[tex]\tt x=\dfrac{1000.e}{96500}=0.0104e[/tex]
For 5x grams :
[tex]\tt 5x=\dfrac{e.Q}{96500}\\\\5\times 0.0104e=\dfrac{e.Q}{96500}\\\\Q=\dfrac{96500\times 5\times 0.0104e}{e}=5018~C[/tex]