Answer:
The Cell Wall
Explanation:
How can we protect space shuttles or astronauts from space radiation in the absence of the atmospheric layer?
What is the role of gravity in maintaining the atmospheric layer around the earth ?
Please put your answers with clear explanation.
Thank you !
Answer:Earth's protective magnetic bubble, called the magnetosphere, deflects most solar particles. ... The International Space Station cruises through low-Earth orbit, within Earth's protection, and the station's hull helps shield crew members from radiation too.☘
have a nice day
Increasing the temperature of a particular liquid from 298 K to 318 K causes its vapor pressure to double. What is the enthalpy of vaporization of this liquid
Answer:
27.3 kJ/mol
Explanation:
Step 1: Given data
Temperature 1 (T₁): 298 KVapor pressure 1 (P₁): P₁Temperature 2 (T₂): 318 KVapor pressure 2 (P₂): 2 P₁Step 2: Calculate the enthalpy of vaporization of this liquid
We will use the Clausius–Clapeyron equation.
ln (P₂/P₁) = -ΔHvap/R × (1/T₂ - 1/T₁)
ln 2 = -ΔHvap/(8.314 J/K.mol) × (1/318 K - 1/298 K)
ΔHvap = 2.73 × 10⁴ J/mol = 27.3 kJ/mol
If the initial amount of indium-117 is 5.2 g, how much indium-117 is left in the body after 86 min
how many moles of H2o are equivelant to 97.3g h2o
Answer:
Number of mole in H2O = 5.4 moles
Explanation:
Given:
Mass of H2O = 97.3 gram
Find:
Number of mole in H2O
Computation:
We know that molar mass of H2O = 18 g/mole
So,
Number of mole = Given Mass / Molar mass
Number of mole in H2O = Mass of H2O / Molar mass of H2O
Number of mole in H2O = 97.3 / 18
Number of mole in H2O = 5.4055
Number of mole in H2O = 5.4 moles
Iodine-131 is administered orally in the form of NaI(aq) as a treatment for thyroid cancer. The half-life of iodine-131 is 8.04 days. If you begin with 34.7 mg of this isotope, what mass remains after 8.52 days have passed
Answer:
16.6 mg
Explanation:
Step 1: Calculate the rate constant (k) for Iodine-131 decay
We know the half-life is t1/2 = 8.04 day. We can calculate the rate constant using the following expression.
k = ln2 / t1/2 = ln2 / 8.04 day = 0.0862 day⁻¹
Step 2: Calculate the mass of iodine after 8.52 days
Iodine-131 decays following first-order kinetics. Given the initial mass (I₀ = 34.7 mg) and the time elapsed (t = 8.52 day), we can calculate the mass of iodine-131 using the following expression.
ln I = ln I₀ - k × t
ln I = ln 34.7 - 0.0862 day⁻¹ × 8.52 day
I = 16.6 mg
The limiting reactant in a chemical reaction is the reactant __________ Select one: A. for which you have the lowest mass in grams. B. which has the lowest coefficient in the balanced equation. C. which has the lowest molar mass. D. which is left over after the reaction has gone to completion. E. None of the above.
Answer:
i think its A
Two planets have similar masses but differ in their distances from the Sun.
Which planet experiences a greater gravitational force with the Sun?
A. The planet that is smaller in volume
B. The planet that is larger in volume
C. The planet that is farther from the Sun
D. The planet that is closer to the Sun
Answer:
D. The planet that is closer to the Sun
To make a 0.500 M solution, one could take 0.500 moles of solute and add Group of answer choices enough solvent to make 1.00 kg of solution. enough solvent to make 1.00 L of solution. 1.00 L of solvent. 1.00 kg of solvent.
Answer: The correct option is enough solvent to make 1.00 L of solution
Explanation:
A solution consists of solute and solvent. A solute is defined as the component present in a smaller proportion while the solvent is defined as the component that is present in a larger proportion.
Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:
[tex]Molarity=\frac{Moles}{Volume}[/tex] .......(1)
We are given:
Molarity of solution = 0.500 M
Moles of solute = 0.500 moles
Putting values in equation 1, we get:
[tex]0.500mol/L=\frac{0.500mol}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{0.500mol}{0.500mol/L}=1.00L[/tex]
Hence, the correct option is enough solvent to make 1.00 L of solution
Which pair of compounds has the same empirical formula?
1.
C2H2 and C6H6
2
C2H6 and C3H8
3.
CH3OH and C2H5OH
4.
CH3CHO and CH3COOH
Explanation:
Correct option is
B
CH
3
COOH
Empirical formula of Glucose C
6
H
12
O
6
= C
1
H
2
O
1
Now, Empirical formula of CH
3
COOH=C
1
H
2
O
1
As empirical formula is the simplest whole number ratio of number of different types of atoms present in the given molecular formula.
Phosphorus -32 is a commonly used radioactive nuclide in biochemical research, particularly in studies of nucleic acids. The half-life of phosphorus-32 is 14.3 days. What mass of phosphorus-32 is left from an original sample of 175 mg of Na332PO4 after 35.0 days
Answer: The mass of P-32 left from the original sample is 32.07 mg
Explanation:
All radioactive decay processes follow first-order reactions.
Calculating rate constant for first order reaction using half life:
[tex]t_{1/2}=\frac{0.693}{k}[/tex] .....(1)
[tex]t_{1/2}[/tex] = half life period = 14.3 days
k = rate constant = ?
Putting values in equation 1:
[tex]k=\frac{0.693}{14.3days}\\\\k=0.0485days^{-1}[/tex]
The integrated rate law equation for first-order kinetics:
[tex]k=\frac{2.303}{t}\log \frac{a}{a-x}[/tex] ......(2)
Given values:
a = initial concentration of reactant = 175 mg
a - x = concentration of reactant left after time 't' = ? mg
t = time period = 35.0 days
Putting values in equation 2:
[tex]0.0485days^{-1}=\frac{2.303}{35.0 days}\log (\frac{175}{a-x})\\\\\log (\frac{175}{a-x})=\frac{0.0485\times 35.0}{2.303}\\\\\log (\frac{175}{a-x})=0.737\\\\\frac{175}{a-x}=10^{0.737}\\\\a-x=\frac{175}{5.457}=32.07mg[/tex]
Hence, the mass of P-32 left from the original sample is 32.07 mg
the density of gold is 19.3 g/ml. if you had a cube made of pure gold that weighs 58.1 pounds what would be the lengh of a side of this cube
Answer:
11.1 cm
Explanation:
First we convert 58.1 pounds into grams:
58.1 lb * [tex]\frac{453.592g}{1lb}[/tex] = 26353.69 gThen we calculate the volume of the gold cube, using the given density:
26353.69 g ÷ 19.3 g/mL = 1365.48 mL
1365.48 mL is equal to 1365.48 cm³.With the volume of a cube we can calculate the side length:
Length = ∛(1365.48 cm³) = 11.1 cmUpon decomposition, a sample of sodium bicarbonate produces 0.0118 g of sodium carbonate, Na2CO3. How many grams of water does it produce
Answer:
2.00 × 10⁻³ g
Explanation:
Step 1: Write the balanced decomposition reaction
2 NaHCO₃ ⇒ Na₂CO₃ + CO₂ + H₂O
Step 2: Calculate the moles corresponding to 0.0118 g of Na₂CO₃
The molar mass of Na₂CO₃ is 105.99 g/mol.
0.0118 g × 1 mol/105.99 g = 1.11 × 10⁻⁴ mol
Step 3: Calculate the moles of H₂O produced with 1.11 × 10⁻⁴ moles of Na₂CO₃
The molar ratio of Na₂CO₃ to H₂O is 1:1. The moles of H₂O produced are 1/1 × 1.11 × 10⁻⁴ mol = 1.11 × 10⁻⁴ mol.
Step 4: Calculate the mass corresponding to 1.11 × 10⁻⁴ moles of H₂O
The molar mass of H₂O is 18.02 g/mol.
1.11 × 10⁻⁴ mol × 18.02 g/mol = 2.00 × 10⁻³ g
A rod “X”, has a positive charge of 5. An otherwise identical rod, “Y”, has a negative charge of 12.
The rods are touched together and then separated.
a) When they touched, what particles moved between them?
b) Did the particles move from “X” to “Y” or from “Y” to “X”.
Answer:
a) electrons
b) from Y to X
Explanation:
positive protons are the cores of atoms in relative to electrons very, very heavy.
the outer electrons of atoms can move, under certain conditions, away from the atom, leaving it electrically unbalanced -> positively charged
there can also be a surplus of electrons on many surfaces, leading to a static negative charge. you know this when you are charged and you discharge with an object or another person, electrically balancing the two bodies charge.
electrons are also much smaller. they are the "things" to move, let it be trough the air or trough a wire, while the heavy protons will stay in place (unless the materials is melted of course, extreme heat brakes the bounds between atoms relatively well)
Francine makes several measurements of the mass of a metal block. The data set is shown in the table below.
Measurement
Mass of metal block (g)
1
20.73
2
20.76
3
20.68
4
20.75
After analyzing this data set, Francine calculates a value of 20.73 g.
Which of these characteristics has been calculated?
mean
median
mode
range
Answer:
Mean
Explanation:
The mean of a series of measurements is calculated when all the measurements are added up and then divided by the number of measurements taken, as follows:
Sum of Measurements = 20.73 + 20.76 + 20.68 + 20.75 = 82.92As there are 4 measurements, the mean is:
Mean = 82.92 / 4 = 20.73Answer:
A
Explanation:
help me plsssssssss.... im timed
Answer:
a
Explanation:
a
Answer:
B. Isotopes of the element.
Explanation:
Isotopes are basically atoms of the same element that contain the same number of protons, but a different number of neutrons.
2. Which of the following equations represents a neutralization reaction?
a. H2CO3 + H2O + CO2
b. 2H2O2 → 2H2O + O2
c. Ba(NO3)2 + K2CO3 →
BaCO3 + 2KNO3
d. HNO3 + NaOH → NaNO3 + H2O
Answer:
d. HNO3 + NaOH → NaNO3 + H2O
Explanation:
Hello there!
In this case, according to the given chemical reactions, it turns out necessary for us to recall the definition of neutralization reaction as those whereby an acid reacts with a base, that is why a, b and c are not within the aforementioned description.
In such a way, we infer the reaction is d. HNO3 + NaOH → NaNO3 + H2O since HNO3 is the acid and NaOH the base.
Regards!
1,500 grams is equal to:
1.5 kg
1.5L
1.5 cm
all of the above
How much energy is released when 2.25kg of water cools from 99.5°C to 4.2°C? 1000g=1kg; 1000J=1kJ; specific heat of water 4.184J/g°C. q=mc∆T
Answer:
897154.2 J
Explanation:
Applying,
q = mcΔT.............. Equation 1
Where q = amount of energy released, m = mass of water, c = specific heat capacity of water, ΔT = Change in temperature
From the question,
Given: m = 2.25 kg = 2250 g, c = 4.184 J/g°C, ΔT = (4.2-99.5) = -95.3°C
Substitute these values into equation 1
q = 2250(4.184)(-95.3)
q = -897154.2 J
q =
Hence the amount of heat released is 897154.2 J
If 0.5 L of O2(g) reacts with H, to produce 1 L of H2O(g), what is the volume of
H2O(g) obtained from 1 L of O2(g)?
-
0.5 L
2.5 L
2 L
1.5 L
Answer:
2 L
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
2H₂ + O₂ —> 2H₂O
From the balanced equation above, we can see clearly that 1 L of O₂ reacted to 2 L of H₂O.
This implies that 2 L of H₂O can be obtained by the reaction of 1 L of O₂.
Thus, option 3 gives the correct answer to the question.
An elementary step is defined as a chemical collision in a reaction mechanism. A collection of different types of collisions makes up the reaction mechanism, so elementary steps provide a molecular view of the overall reaction.
a. True
b. False
Can you help ASAP? Thanks you.
Answer:
ok
Explanation:
The element tin has the following number of electrons per shell: 2, 8, 18, 18, 4. Notice that the number of electrons in the outer shell of a tin atom is the same as that for a carbon atom. Therefore, what must be true of tin
The question is incomplete, the complete question is:
The element tin has the following number of electrons per shell: 2.8. 18, 18, 4. Notice that the number of electrons in the outer shell of a tin atom is the same as that for a carbon atom. Therefore, what must be true of tin? Tin is a polar atom and can bind to other polar atoms. Tin has a high molecular weight to give tin-containing molecules greater stabilty. All of the above Tin conform single covalent bonds with other elements, but not double or triple covalent bonds Tincan bind to up to four elements at a time
Answer:
Tin can bind to up to four elements at a time
Explanation:
Certain important points were made in the question about tin and one of them is that tin is an element in the same group as carbon hence it has the same number of valence electrons as carbon.
Carbon is always tetra valent. The tetra valency of carbon is the idea that carbon forms four bonds.
If tin has the same number of valence electrons as carbon, then, tin can bind to up to four elements at a time
In which of the following molecules is hydrogen bonding likely to be the most significant component of the total intermolecular forces??
a. C6H13NH2
b. CH3OH
c. CH4
d. C5H11OH
e. CO2
Answer:
The given molecules are:
a. C6H13NH2
b. CH3OH
c. CH4
d. C5H11OH
e. CO2
Explanation:
The hydrogen bond is a weak electrostatic force of attarction that exists between covalently bonded hydrogen (of -OH or -NH2 or HF) with a highly electronegative atom like N,O and F.
Hydrogen bonding is of two types:
Intermolecular hydrogen bond (exists between two molecules)
Intramolecular hydrogen bond(exists within a molecule).
For example intermolecular hydrogen bond in water is shown below:
Among the given options,
a. C6H13NH2 has -NH2 linkage which leads to hydrogen bond formation.
b. CH3OH has -OH bond and it leads to hydrogen bond fomation.
d. C5H11OH has also -OH bond and it leads to hydrogen bond fomation.
Reamining molecules, CH4 and CO2 do not form hydrogen bond.
Hence, answer is:
options a,b,d.
a solution that contains a large amount of solute would be described as what
Answer:
A concentrated solution is one that has a relatively large amount of dissolved solute. A dilute solution is one that has a relatively small amount of dissolved solute.
Given the balanced reaction: Zn + 2HCl → H2 + ZnCl2
If 5 grams of each reactant are available for the reaction and HCl is known
to be the limiting reactant, which of the following is correct?
O Both reactants will be completely used up.
O There will be excess of both reactants remaining.
O HCl will be completely used up while Zn will remain in excess.
O Zn will be completely used up while HCl will remain in excess.
Answer:
O HCl will be completely used up while Zn will remain in excess.
Explanation:
Zn + 2HCl → H₂ + ZnCl₂In reactions involving two reactants, if one of them is the limiting reactant then the other one has to be the reactant in excess.
Meaning that in this case, the reaction will proceed until HCl is completely used up, and a certain amount of Zn will remain (thus being the reactant in excess).
Question 13 of 32
The pH of a sample of seawater is 8.0. What is the hydrogen ion concentration of seawater?
A. 8.0 M
B. 1 x 108 M
C. 6.0 M
D. 1 x 10-8 M
Answer:
D
Explanation:
what climate zone is asia?
Answer:
The Tundra Climate
Explanation:
:) hope this helps
if the radius of a potassium atom is 2.27 x 10-7 mm what is the radius in μm
Explanation:
the answer is in the Image above
The radius of the potassium atom is [tex]2.27\times 10^{-4} \mu m[/tex].
Explanation:
Given:
The radius of potassium atom =[tex]2.27\times 10^{-7} mm[/tex]
To find:
The radius of potassium atom in micrometers.
Solution:
The radius of potassium atom =[tex]2.27\times 10^{-7} mm[/tex]
In 1 millimeter there are 1000 micrometers.
[tex]1 mm = 1000 \mu m[/tex]
Then in [tex]2.27\times 10^{-7} mm[/tex]:
[tex]=2.27\times 10^{-7} \times 1000\\=2.27\times 10^{-4} \mu m[/tex]
The radius of the potassium atom is [tex]2.27\times 10^{-4} \mu m[/tex].
Learn more about conversions here:
brainly.com/question/24530464
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At 258C, Kp 5 2.9 3 1023 for the reactionNH4OCONH21s2m 2NH31 g21 CO21 g2In an experiment carried out at 258C, a certain amount of NH4OCONH2 is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.
Answer:
0.27 atm
Explanation:
At 25ºC, Kp = 2.9 x 10⁻³ for the reaction NH₄OCONH₂(s) ⇌ 2 NH₃(g) + CO₂(g). In an experiment carried out at 25ºC, a certain amount of NH₄OCONH₂ is placed in an evacuated rigid container and allowed to come to equilibrium. Calculate the total pressure in the container at equilibrium.
Step 1: Make an ICE chart
Solid and liquids are ignored in ICE charts.
NH₄OCONH₂(s) ⇌ 2 NH₃(g) + CO₂(g)
I 0 0
C +2x +x
E 2x x
Step 2: Write the pressure equilibrium constant expression (Kp)
Kp = [NH₃]² × [CO₂]
Kp = (2x)² × x
2.9 × 10⁻³ = 4 x³
x = 0.090 atm
Step 3: Calculate the pressures at equilbrium
pNH₃ = 2x = 2(0.090 atm) = 0.18 atm
pCO₂ = x = 0.090 atm
The total pressure is:
P = 0.18 atm + 0.090 atm = 0.27 atm
What is homeostasis?
a.
production of urine.
b.
maintaining a stable internal environment.
c.
excretion of waste materials.
d.
none of the above.
Please select the best answer from the choices provided
Answer:
the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Explanation:
