Answer:
lead causes vessels to constrict, limiting the space for blood to flow (compare the size of the red circles.) This narrowing increases blood pressure, forcing the heart to work harder.
Answer:
By mimicking calcium and increasing cell stress, lead causes vessels to constrict, limiting the space for blood to flow. This forces the heart to work harder because the narrowing increases blood pressure.
If the half life of iridium-182 is 15 years, how much of a 3 gram sample is left after 2 half-lives?
A) .57 grams
B) .70 grams
C) 2.25 grams
D) .75 grams
Answer:
D. 0.75 grams
Explanation:
The data given on the iridium 182 are;
The half life of the iridium 182, [tex]t_{(1/2)}[/tex] = 15 years
The mass of the sample of iridium, N₀ = 3 grams
The amount left, N(t) after two half lives is given as follows;
[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}} }[/tex]
For two half lives, t = 2 × [tex]t_{(1/2)}[/tex]
∴ t = 2 × 15 = 30
[tex]\dfrac{t}{t_{(1/2)}} = \dfrac{30}{15} = 2[/tex]
[tex]\therefore N(t) = 3 \times\left (\dfrac{1}{2} \right )^2 = 0.75[/tex]
∴ The amount left, N(t) = 0.75 grams
What is the state of HNO3 in the reaction? HNO3 (g) --> NO2 (g) + 2 H2O (1) 1 point
+ O2 (g)
gas
liquid
aqueous
Answer:
gas
Explanation:
the answer is right in the question (g) stands for gas.
Vhon Anadome
Atomic nucleus questions
Which of the following decay processes results in the largest change in mass of a nucleus?
Choose 1 answer:
А
Beta decay
Gamma decay
Neutron emission
D
Alpha decay
Answer:
d
Explanation:
Determine the volume of a helium balloon given the balloon was filled from a container 0.15L of gas at 2 atm if the new pressure is 0.97 atm. Assume constant temperature.
Answer:
The volume of the helium balloon is 0.306 L.
Explanation:
Boyle's law states that the volume occupied by a given gaseous mass at constant temperature is inversely proportional to pressure. That is, if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases.
Mathematically, Boyle's law indicates that the product of pressure and volume always has the same value:
P*V= k
Assuming that you have a certain volume of gas V1 that is at a pressure P1 at the beginning, by varying the volume of gas to a new value V2, then the pressure will change to P2, and it will be fulfilled:
P1*V1= P2*V2
In this case:
P1= 2 atmV1= 0.15 LP2= 0.97 atmV2= ?Replacing:
2 atm* 0.15 L= 0.97 atm* V2
Solving:
[tex]V2= \frac{2 atm* 0.15 L}{0.97 atm}[/tex]
V2= 0.306 L
The volume of the helium balloon is 0.306 L.
How many moles in 4.65 g of Helium?
Answer:
4.65 g x 1 mol/4.0026 g/mol = 1.162 mol helium
Explanation:
when potassium chloride is dissolved in water *
a)heat is given off
b)heat is taken in
c)temperature stays same
Answer:
Option B . heat is taken in
Answer:
B
Explanation:
we need to eat,drink,and sleep to be healthy
write a chemical equation for action of HBr on ethanol
answer:
hope this one helps have a great day !
Compound A reacts with alcoholic KOH to yield compound B which on ozonolyzises followed by the reaction with Zn/H2O gives methanal and propanal Compound A is
Answer:
1-chlorobutane
Explanation:
Given that :
-- The compound A is made to react with alcoholic KOH and produce compound B.
-- The compound B on Ozonolysis produces methanol as well as propanol
The compound A should be a haloalkanes as treatment of haloalkanes with the alcoholic KOH, it will give alkene.
[tex]$CH_3CH_2CH_2CH_2Cl+KOH( \text{alcohol}) \rightarrow CH_3CH_2CH=CH_2+KCl+H_2O$[/tex]
So, the compound B should be Butene
Now the ozonolysis of the compound B or butene will give methanol and propanal as shown :
[tex]$CH_3CH_2CH=CH_2 \rightarrow CH_2O+CH_3CH_2CHO$[/tex]
Therefore, the compound A is 1-chlorobutane.
Which of the following represents an element ? H2O H2 NaCl CaCO3
Answer:
H₂
Explanation:
H₂ is hydrogen in its elemental form.
H₂O, NaCl, and CaCO₃ are all examples of elements added together to create compounds.
Find the area of the sector with a central angel of 120 and a radius of 8 inshces. Leave in terms of pie
Answer:
A = 66.98 square in.
Explanation:
The Area of a sector is given by the formula
[tex]A = \frac{\theta}{360}\times \pi r^2[/tex]
here θ is the central angle and r is the radius
given that θ = 120° and radius = 8 inches
[tex]A = \frac{120}{360}\times3.14\times 8^2[/tex]
A = 66.98 square in.
The photograph below shows the East African Rift Valley in Africa. Which tectonic movement
of Earth’s crust is most likely responsible for this feature?
Answer:
divergence of continental crust
Explanation:
lime water turns milky when carbon dioxide gas passed through it and on further exposure to carbon dioxide the milkiness disappear, why
Resultant carbon dioxide passed through limewater in the right tube, producing a milky solution due to precipitation of the insoluble suspension of calcium carbonate: ... The milkiness disappears since calcium bicarbonate is water-soluble.
Aqueous solutions of a strong acid and a weak acid of equal concentrations are compared. Which of the following statements are true?
I. The strong acid reacts with a metal oxide but the weak acid does not
II. The weak acid is less disassociated than the strong acid
III. The strong acid has a greater conductivity that the weak acid.
Answer:
Explanation:
A gas fills up a container that has 2.5L has a pressure of 3.5 atm. If the gas gets transferred to a container that holds 4L, what would the new pressure be?
Witch part of an atom is mostly empty space?
5. The bond in a molecule of Cl2 could be described as
A. covalent
O B. ionic
C. both A and B
O D. neither A nor B
the bond in a molecule of Cl2 is a covalent bond
How would the balloons interaction with each other change if the balloons were moved further apart? Explain.
Explanation:
It is known that like charges repel each other and unlike charges attract each other.
As the balloons are facing each other with like charges so they will repel each other. Hence, they will move apart.
But when balloons were moved further apart then interaction between them will decrease and then there will be no force of repulsion or force of attraction.
I need to know the coefficient order
Explanation:
in mathematics use Pascal triangle
A test light with an electrical resistance of 9.00 S2 draws a current of 1.50 A when
it is connected to an electrical source. How much power does the light use?
Answer:
20.25 W
Explanation:
Applying,
P = I²R.................... Equation 1
Where P = Power, I = current drawn by the test light, R = Resistance of the test light
From the question,
Given: I = 1.5 A, R = 9.00 Ω
Substitute these values into equation 1
P = (1.5²)(9)
P = 2.25×9
P = 20.25 W
Write a nuclear equation for the beta decay of Promethium-165
Answer:
see your answer in pic
Explanation:
There can be emissions of radiations like gamma radiation. There can be emission of particles too like alpha particle. Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
What is nuclear decay?Nuclear decay is process in which the radioactive element releases particles or radiations. Alpha particles is ⁴₂He. Alpha particle is nothing but helium particle. The kinetics that is related to nuclear decay is of first order.
The nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
Beta decay of Promethium-165 is the emission of electron particle from the given isotope. the product is Samarium ₆₂Sm¹⁶⁵.
Therefore, the nuclear equation for the beta decay of Promethium-165 is
¹⁶⁵Pm[tex]\rightarrow[/tex]⁰e₋₁ + ₆₂Sm¹⁶⁵
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can u pls answer 22, 23, 24
Answer:
I'm terribly sorry but the download is not working for me! All it says is Download pdf, and when I click it, It does nothing except for refreshing the page!
Explanation:
Can someone help me
Answer:the second largest one
Explanation:
both weels are pushing at it
Suppose I have enough ingredients to make 25 cookies, but when I go to bake them, I only get 5. What percent yield did I obtain?
Answer:
Explanation:
What is the "theoretical yield" of cookies from each of the "reactants?"
Theor. yield from eggs
=
12
eggs
×
24 cookies
1
egg
=
288 cookies
Theor. yield from vanilla
=
24
tsp vanilla
×
24 cookies
1
tsp vanilla
=
576 cookies
Theor. yield from salt
=
82
tsp salt
×
24 cookies
0.5
tsp salt
=
3936 cookies
Theor. yield from baking soda
=
84
tsp baking soda
×
24 cookies
0.5
tsp baking soda
=
4032 cookies
Theor. yield from chocolate chips
=
3
cups chocolate chips
×
24 cookies
1.333
cups chocolate chips
=
54 cookies
Theor. yield from sugar
=
11
cups sugar
×
24 cookies
0.5
cup sugar
=
528 cookies
Theor. yield from brown sugar
=
4
cups brown sugar
×
24 cookies
0.5
cup brown sugar
=
192 cookies
Finally, "we leave it as an exercise for the student" to calculate that
Theor. yield from margarine = 72 cookies
b. Identify the limiting reactant
The limiting reactant is the amount of chocolate chips because they can produce the smallest amount of cookies.
c. Determine the theoretical yield
The theoretical yield is 54 cookies, because that is all you can get from the chocolate chips provided.
The percent yield obtained on baking the cookies is 20 % and the theoretical yield is 25 cookies.
What is percent yield?Percent yield is defined as the ratio of actual yield to the theoretical yield multiplied by 100. If the actual and theoretical yield are same then the percent yield is 100%.If actual yield is less than the theoretical yield then the percent yield is less than 100%.Reason of this condition arising is the incompletion of reaction or loss of sample during recovery process.
In cases where percent yield is over 100% it indicates that more sample is recovered than the predicted amount.This condition arises when there are other simultaneous reactions taking place leading to the formation of product. It can also arise if there is incomplete removal of impurities from the sample .
As cookies obtained is 5 it is observed yield while 25 is theoretical yield so the percent yield, 5/25×100=20%.
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Please help!!!!!!!!!!!!!!!!!!!
Answer:
Hydrochloric acid + calcium hydroxide = calcium chloride + water
HELP ASAAAAP 40 MINS LEFT AAA!
Geometric isomers have profound effects on the physical properties of compounds. Naturally occurring fatty acids generally adopt a cis geometry. What's one physical property affected by this geometry?
A)
Color
B)
Taste
C)
Smell
D)
Melting point
Most terrestrial plants are members of this Division:
Bryophyta
Angiosperms
Pinophyta
Pteridophyta
Answer:
most flowering plants are classified as angiosperms
Answer:
I think the answer is Bryophyta
Explanation:
seedless,non vascular plants that are the closest extant relative of early terrestrial plants
Name two types of silk
Answer:
Tussar silk
Charmeuse
Explanation:
Hope this helps! :)
1. BaBr2(aq) + H2SO4(aq) →?
please balance the equation and predict the products
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.
Part of Newtons first law states an object at rest stays at rest unless acted upon by an unbalanced force. Which one is NOT an example of this law?
Solution :
Sir Isaac Newton was a great scientist. The discoveries of the Newton change the way we see the world. Newton gave us the fundamental principles through which the entire universe is governed.
Newtons 1st law of motion states that a body moves or stays in position until and unless an external force is applied to the body.
This is the law of nature.
An example which do not support this law can be a body having a huge mass and a small boy applies force to move it but is unable to move the body.
Which atom attracts electrons most strongly? br F Rb
Fluorine has the highest electronegativity in comparison to other elements therefore, the F atom attracts electrons most strongly.
What is electronegativity?The electronegativity of an atom measures the tendency of an element to attract the bonded electrons pairs towards itself. The electronegativity of an atom is determined with respect to another bonded atom.
Electronegativity can be described as a chemical property of an atom or a functional group to attract electrons toward itself. The electronegativity of an atom depends on the atomic number and the distance of valence electrons from the charged nuclei.
When two different atoms are bonded through a bond. More electronegative will attract the electron density of the bond towards itself.
As we know, the electronegativity decreases as we move down the group in the periodic table. Fluorine is the most electronegative element in the periodic table therefore, Fluorine (F) will attract the electrons toward it most strongly.
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