Answer:
nitrogen 18
nitrogen has an atomic number of 7
PLEASE HELP!!!!!
What happens to the transfer of thermal energy when thermal equilibrium is reached?
Answer:
During the process of reaching thermal equilibrium heat is transferred between the object. heat is always transferred from the object at the higher temperature to the object with lower temperature. For a gas, the heat transfer is related to a change in temperature.
16.4 A cylinder of water contains oxygen in solution. The cross- sectional area of the cylinder is 2 cm2 and the length of the cylin- der is 5 cm. At one end of the cylinder the concentration of oxygern is maintained at 0.2 mol m-3, this concentration falls linearly to 0.05 mol m-3 at the other end of the cylinder. The diffusion con- stant of oxygen in water is 8 × 10-10 m2 s-1. How many moles of oxygen pass down this cylinder every second? What mass of oxy- gen passes down the cylinder each second?
Answer:
A) oxygen moles/sec = 48 * 10 ^-14 mol/sec
B) mass of oxygen = 1536*10^-14 grams
Explanation:
cross sectional area of cylinder = 2cm^2 = 2 * 10^-4 m^2
length of cylinder = 5 cm = 0.05 m
concentration at one end = 0.2 mol m^-3
concentration falls linearly at other end = 0.05 mol m^-3
Diffusion constant of oxygen = 8 * 10^-10 m^2 s^-1
A ) Number of moles of oxygen passing every second
N = A * D * [tex]\frac{dc}{dt}[/tex] ------- ( 1 )
A = area , D = diffusion constant, [tex]\frac{dc}{dt}[/tex] = rate of change of diffusion
dc /dt = ( 0.2 - 0.05 ) / 0.05 = 3 mol m^-4
back to the equation
N = ( 2 * 10^-4 ) * ( 8 * 10^-10 ) * ( 3 ) = 48 * 10 ^-14 mol/sec
B) Mass of oxygen passing down the cylinder each second
This can be obtained by converting : 48 * 10^-14 moles to grams
1 mole of oxygen = 32 grams of oxygen
therefore : 48 * 10^-14 moles of oxygen = ( 32 * (48*10^-14) = 1536*10^-14 grams
How many lead (Pb) atoms are in a 5.32 g sample of pure lead?
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
what istope of an atom if it has 29 protons and 36 neutrons?
Answer:
Copper Atoms
Explanation:
All copper atoms have atomic number 29: all their nuclei contain 29 protons. But they also contain uncharged particles called neutrons. In natural copper, the atoms are of two kinds. One has 29 protons and 34 neutrons in the nucleus; the other has 29 protons and 36 neutrons
Compounds have the same properties as the elements they are made up of. Is it true or false
Answer:
compounds have the same properties the elementary are false.
7. Which of the following units would be MOST appropriate for measuring
the volume of a small can of soda? *
1 point
A. Liters
B. Milliliters
C. Grams
D. Kilograms
Use the metric ruler to answer questions 8 and 9.
Answer:
im pretty sure the answer is b
[tex]\\\\\\[/tex]
HOPE IT HELPS
PLEASE MARK ME BRAINLIEST ☺️
If 298 mL of 0.575 M CuCl2 is diluted into 750 mL, what is the concentration of new solution?
Answer:
The answer is 0.228 MExplanation:
To find the concentration of new solution we use the formula
[tex]C_1V_1 = C_2V_2[/tex]
where
C1 is the concentration of the stock solution
V1 is the volume is the volume of the stock solution
C_2 is the concentration of the diluted solution
V2 is the volume of the diluted solution
Since we are finding the the concentration of new solution
[tex]C_2 = \frac{C_1V_1}{V_2} \\[/tex]
From the question
C1 = 0.575 M
V1 = 298 mL
V2 = 750 mL
We have
[tex]C_2 = \frac{0.575 \times 298}{750} \\ = 0.228466666...[/tex]
We have the final answer as
0.228 MHope this helps you
Using the formula Q = m x ^T x Cp, solve for energy, and round your answer to the correct number of sig figs and show all work:
1) How much heat is absorbed by 1210. g water (Cp = 4.184 J/g*C) when it is heated from 20*C to 45*C
Answer:
Q = 126.5 kJ
Explanation:
Given that,
Mass, m = 1210 g
Specific heat of water, c = 4.184 J/g°C
Initial temperature, [tex]T_i=20^{\circ} C[/tex]
Final temperature, [tex]T_f=45^{\circ} C[/tex]
We need to find the heat absorbed by water. The formula that is used to find the heat absorbed is given by :
[tex]Q=mc\Delta T[/tex]
Putting all the values in it we get :
[tex]Q=1210\ g\times 4.184\ J/g^{\circ} C\times (45-20)^{\circ} C\\Q=126566\ J\\\\\text{or}\\\\Q=126.5\ kJ[/tex]
So, the amount of heat absorbed is 126.5 kJ.
A compound has the following composition by mass:
32% carbon, 6.7% hydrogen, 42.6% oxygen and 18.7% nitrogen
What is the empirical formula of the compound?
Answer:
i cry when im alone
Explanation:
Marcy tests a solution with a strip of blue litmus paper. The paper turns red. The solution is _____.
acidic
basic
neutral
A scientist is studying two types of worms. Worm X has DNA identical to its parent. Worm Y has a combination of DNA from two parents. The scientist determines that one of the worms has a survival advantage over the other worm. Which statement correctly summarizes this conclusion? Worm X reproduces asexually, which gives it genetic variation. Worm Y reproduces sexually, which gives it genetic variation. Worm Y reproduces asexually, which gives it more DNA. Worm X reproduces sexually, which gives it more DNA.
Answer:
2. Worm Y reproduces sexually, which gives it genetic variation.
Answer:
B Worm Y reproduces sexually, which gives it genetic variation.
Explanation:
hope you all have a good day
What is the term for an object's strength of motion?
O Momentum
O Acceleration
O
Force
O
Velocity
I'm pretty sure its momentum
What is the density (g / mL) of a substance that has a mass of 8.11 g and, when placed into a graduated cylinder, causes the water level to rise from 25.26 mL to 44.72 mL?
Answer:
The answer is 0.42 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass = 8.11 g
volume = final volume of water - initial volume of water
volume = 44.72 - 25.26 = 19.46 mL
We have
[tex]density = \frac{8.11}{19.46} \\ = 0.416752312...[/tex]
We have the final answer as
0.42 g/mLHope this helps you
Which of the following is a common sign that a chemical change has occurred?
Which organ produces the female hormone estrogen?
A. Hypothalamus
B. Ovary
C. Pancreas
D. Testicle
Answer:
b-ovaries
Explanation:
Answer:
ovaries
Explanation:
i just know trust me tell me if its wrong
What do organs combine to form? organ systems cells tissues organisms
Answer:
the answer is {organisms}
Answer:
organisms
Explanation: I took the test
To convert measurements in the metric system you can move the decimal point left or right why does this work?
Explanation:
Because when you move the decimal point once, it it equal to 10 and to convert in the metric system, you must multiply or divide by 10. For example, when converting 4 centimeters to millimeters, you can multiply by 10 to get 40 millimeters or you can move the decimal point to the right and add another 0 to get 40.
Answer:
when you move tne decmal point it alwase ads up to ten
Explanation:
Which of the statements below about buoyancy is true?
A.if the buoyant force is greater than the force of gravity,the object will sink
B.buoyancy is a force that acts on objects that are placed in a fluid
C.all objects that experience the force of buoyancy float
D.buoyancy pushes objects down in the same direction as gravity
(answer asap plz I will give brainliest to who helps me )
Answer:
it's A. if the force of gravity is greater than the buoyant force, the object will sink.
Explanation:
just took the quiz on a p e x
A testable explanation of or answer to a scientific question that is based on prior knowledge or research is a(n)
Answer:
the answer is HYPOTHESIS your welcome
Explanation:
Where can you find most of Earth's liquid freshwater?
Answer:
Where can you find most of Earth's liquid freshwater?
Explanation:
Over 68 percent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 percent is found in ground water. Only about 0.3 percent of our fresh water is found in the surface water of lakes, rivers, and swamps.
Hope that helped, i also have snap if you need me.
Over 68 per cent of the fresh water on Earth is found in icecaps and glaciers, and just over 30 per cent is found in groundwater. Only about 0.3 per cent of our freshwater is found in the surface water of lakes, and rivers.
What is the per cent of the water on this earth?The Earth is a watery place. About 71 per cent of the Earth's surface is water-covered, and the oceans hold about 96.5 per cent of all Earth's water.
The majority of Earth’s fresh water is stored in underground aquifers.
Aquifers are layers of sedimentary formations such as sandstone and fractured hard rocks where water after infiltration from soil reaches and fill the interstitial spaces.
Aquifers are huge in size in basins and contain a huge amount of underground water of fresh quality.
So, over 68 per cent of the freshwater is present on Earth.
Learn more about the freshwater here:
https://brainly.com/question/4381433
#SPJ2
Which pair has the stronger ionic bond:
- MgCl2 vs. NaCl2
- NaCl vs. LiCl
Is a venus fly trap non-living?
What allows a liquid to take the form of the container it is in?
A.
strong intermolecular forces
B.
low temperature
C.
weak intermolecular forces
D.
low kinetic energy
Answer:
It's probably C
The forces between liquid particles are weaker than the forces between solid particles. This means that liquid particles are further apart and can move about more easily. Since the particles can move, the liquid can flow and take the shape of its container
Sorry if the answer is wrong!!!!!!
✓7
Is it rational or irrational
Answer:
Irrational
Explanation:
:)
Answer:
It is irrational
Explanation:
Since 7 is a prime number, it has no square factors and its square root cannot be simplified.
5) Which of these are intensive properties?
a substance has a volume of 5.4 mL
a substance has a mass of 1.25 g
a substance has a density of 4.13 g/cm3
a substance has a melting point of 40°C
a substance is very malleable (it can be hammered into a shape)
6) Which of these are extensive properties?
a substance has a melting point of 40°C
a substance is very malleable (it can be hammered into a shape)
a substance has a volume of 5.4 mL
a substance has a mass of 1.25 g
a substance has a density of 4.13 g/cm3
Answer:
For number 5 it is the 2nd one some stants has a mass of 1.25 g And the 2nd 1 number 6It is the 1st 1A subject has a melting point of 40
Which is a feature of a single replacement reaction?
Substance XYZ breaks down into X and YZ.
Substance G reacts with compound XY to form GY and X.
Substance X burns rapidly in the presence of oxygen.
Substance QR and GT exchange ions with each other.
Answer:
Its B
Explanation:
Because im just built different
The statement featuring the single replacement reaction has been statement B.
The single replacement reaction has been defined as the reaction of the highly reactive element with the compounds, that results in the formation of the new compound with the replacement of the less reactive element.
The single replacement reaction can be given as:
G + XY [tex]\rightarrow[/tex] GY + X
In the reaction, G being more reactive than X has been able to displace X and forms bond with Y. Thus, statement featuring the single replacement reaction has been B.
For more information about the single replacement reaction, refer to the link:
https://brainly.com/question/8625202
Ionic crystals have high boiling points because:
A. They do not have high boiling points.
B. breaking ionic bonds requires a large amount of energy.
C. the structure has a large surface area to absorb heat quickly.
D. the positive and negative charges prevent them from absorbing heat quickly.
The answer would be B.
Calculate the number of grams of CuSO4 found in 3.29 mL of a 4.00 M CuSO4 solution. ______ grams CuSO4
Answer:
2.08g
Explanation:
Given parameters:
Volume of CuSO₄ = 3.29mL
Molarity = 4M
Unknown:
Mass of CuSO₄ = ?
Solution:
Let us find the number of moles from the given parameters first;
Number of moles = molarity x volume
1000mL = 1L
Express the volume of the given CuSO₄ in L = 3.29 x 10⁻³L
Number of moles = 4 x 3.29 x 10⁻³ = 0.013mol
So;
Mass of CuSO₄ = number of moles x molar mass
Molar mass of CuSO₄ = 63.6 + 32 + 4(16) = 159.6g/mol
Mass of CuSO₄ = 0.013mol x 159.6g/mol
Mass of CuSO₄ = 2.08g
What is the enthalpy of reaction for the decomposition of calcium carbonate?
CaCO3(s) Right arrow. CaO(s) + CO2(g)
Answer:
Explanation:
You will need to look up the Standard Heats of Formation* for each substance and apply Hess's Law Equation.
ΔH⁰(rxn) = ∑ΔH⁰(Products) - ∑ΔH⁰(Reactants)
*Std Heats of Formation can be found in the appendix of most college chem texts.
For this problem:
Given CaCO₃(s) => CaO(s) + CO₂(g)
∑ΔH⁰: -635.1 Kj/mole -393.5Kj/mole -1206.9
ΔH⁰(rxn) = [(-393.5 Kj/mole) + (-393.5Kj/mole)] - (-1206.9Kj/mole)
= (-635.1 -393.5 + 1206.9) Kj/mole
= +178.3 Kj/mole
Answer:
656.3 kJ
This reaction is endothermic
Explanation:
edge 2020
Use the periodic table to determine the electron configuration for aluminum (Al) and arsenic (As) in noble-gas notation.
Al:
[Ar]3s23p1
[He]2s22p63s23p1
[Ne]3s23p1
[Ne]3s23p2
Answer:
C
Explanation:
[Ne]3s23p1
Answer:
C
Explanation: