Answer:
chemical equation balance.
Explanation:
if you need more explanation , comment.
A runner completes a 400m race in 43.9s. What is his average speed?
Answer:
average speed around 9.1 meters/second
Explanation:
400 divided by 43.9
1. The human eye can detect wavelengths of light as short as 0.000037 cm. What is this
wavelength in nanometers?
Answer:
0.000037 cm is 370 nanometers
Explanation:
Which of the following happens to the particles when the temperature of liquid water drops?
Explanation:
when water is in liquid form and the temperature DROPS it becomes solid ice the process is melting , freezing and evaporation this goes in a circle
Which of the following is considered a sign of a chemical change?
How many moles of gold, a U, are in 3.60×10^-5 G of gold?
Answer:
See Below.
Explanation:
This is a conversion problem:
Using the molar mass of Gold (given in a periodic table) which is 196.97g/mol
you have
[tex](3.60*10^-5 g) *\frac{1moles}{196.97g}[/tex]
you always arrange the equation in a way to cancel whatever you don't want (grams) and leave what you do want (moles). Here grams cancel (top and bottom), so you're left with:
[tex]\frac{(3.60*10^-5 g) *(1)}{196.97} = 1.83*10^-7[/tex] moles of Gold
Select the molecular shape of each molecule based on the formula or Lewis structure.
Answer:
1. linear (A)
2. trigonal-planar (C)
3. tetrahedral (B)
4. linear (A)
Explanation:
Just did it on Edge 2020
The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
The Valence Shell Electron Pair repulsion theory gives us a basis for predicting the shape of molecules. The shape of a molecule can be predicted from the number of electron pairs that surround the central atom in the molecule.
In the image shown, We can see that in HCN , carbon is the central atom and is surrounded by two atoms and no lone pairs. Since there are two electron domains around the central atom, the molecule is linear.
In the second structure, BH3 has boron as its central atom. Three electron domains surround the central atom hence the molecule is trigonal planar.
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How is heat transferred when you touch an ice cube?
Answer:
The heat is transferred from your hand to the ice, this is because, as we know, heat gets transferred from a hot object to a colder object.
In this case, our hand is clearly hotter than the ice cube.
Therefore, the heat is transferred from your hand to the ice cube.
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Explain why the mass number of oxygen is 16
Answer:
Oxygen has an atomic number of 8 , and the mass number of an atom is the sum of its atomic number plus its neutron number. We got the mass as 16 units, and so it'll have 16−8=8 neutrons.
Explanation:
How many moles are in 5.25 X 10 25
atoms of Au?
Answer:
The answer is 87.21 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\ [/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{5.25 \times {10}^{25} }{6.02 \times {10}^{23} } \\ = 87.2093023...[/tex]
We have the final answer as
87.21 molesHope this helps you
With circulation, the heart provides your body with:
a. oxygen
b. nutrients
C. a way to get rid of waste
d. all of the above
Explanation:
The lungs pump oxygen in and carbon dioxide out, which goes through the blood stream to help with the cell's energy needs.
Nutrients pass through the blood stream as well. The nutrients start with the digestive system (mouth, esophagus, stomach, small intestine) before going into the blood stream. The nutrients are building blocks to help make new cells when old ones die off.
When those cells die off, the body sheds them like dead skin, but internal dead cells are passed off as waste. This waste and other byproducts the body doesn't need passes through the blood stream as well.
In short, the blood stream is basically the highway to help get desired materials (eg: oxygen and nutrients) and get rid of waste (eg: carbon dioxide and other unwanted byproducts or dead cell material)
So that's why the answer includes A, B and C.
Which types of reactions would result in the formation of precipitate?
Answer:
Double Displacement Reaction
Explanation:
A double displacement reaction is a type of chemical reaction in which the reactant ions exchange places to form new products. Usually, a double displacement reaction results in precipitate formation.
Diffusion of Ammonia in an Aqueous Solution. An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface. The concentration of ammonia in the organic phase is held constant and is such that the equilibrium concentration of ammonia in the water at this surface is 2.0 wt 'Yo ammonia (density of aqueous solution is 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density of 961.7 kg/m3). Water and the organic are insoluble in each other. The diffusion coefficient ofNH3 in water is 1.24 x 10- 9 m 2/sCalculate the flux N_B. Explain.
Answer:
The Flux N_B = 0
Explanation:
So, we are given the following set of data or parameters which is going to help in solving this particular Question. So, let us take each at a time;
=> "An ammonia (A)-water (B) solution at 278 K and 4.0 mm thick is in contact at one surface with an organic liquid at this interface."
=>" 2.0 wt 'Yo ammonia (density of aqueous solution is 991.7 kg/m3) and the concentration of ammonia in water at the other end of the film 4.0 mm away is 10 wt % (density of 961.7 kg/m3). ''
With the information above, we can determine the N_A(which the question did not specify that we should calculate).
For the value of N_B, it will be equals to zero(0) because the insolubility of water in organic solvent.
How many d electrons does I (atomic number
53) possess?
1. 10
2. 5
3. 8
4. 0
5. 20
6. 53
7. 16
Answer:
6. 53 is the answer. Hope this helps:)
The number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
What is an Atomic number?An atomic number may be defined as the number of protons in the nucleus of an atom that significantly represents the characteristic of a chemical element and determines its specific place in the modern periodic table.
According to the modern periodic table, an element that has an atomic number of 53 is known as Iodine. Its electronic configuration is [tex]1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^1^0, 4p^6, 5s^2, 4d^1^0, 5p^5[/tex]. Thus, according to this electronic configuration, the total number of d electrons are [tex]3d^1^0 and 4d^1^0[/tex].
Therefore, the number of d electrons that an atom of atomic number 53 possess are 20. Thus, the correct option for this question is 5.
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Answer question number 3
What happens to the atomic radius when an electron is lost?
A. The positive ionic radius is the same size as the neutral atomic
radius.
B. The positive ionic radius does not follow a trend with the neutral
radius.
C. The positive ionic radius is smaller than the neutral atomic radius.
D. The positive ionic radius is larger than the neutral atomic radius.
Answer:the positive ionic radius is smaller than the neutral atomic radius
Explanation:
Answer:The positive ionic radius is smaller than the neutral atomic radius.
Explanation: just took the test
What physical property of the metal rods was being tested during step 4 of the procudure?
4. Measure and record how long it takes heat from the hot plate set on "high" to melt the wax ball.
A.
magnetism
B.
thermal conductivity
C.
electrical conductivity
D.
density
Answer:
B. thermal conductivity
Explanation:
They physical property being tested during the fourth step is the thermal conductivity of the materials.
Thermal conductivity is the ability of a body to transmit heat energy from one place to another.
Since we are measuring how long it takes for heat from the hot plate to reach the wax ball, this is a typical experiment for measuring thermal conductivity. Most metals are good conductors and heat energy moves fast in them.Non-metals are poor conductors with low thermal conductivity.What type of heat transfer happens in the Inner Core?
Answer: Conduction
Explanation:
PLEASE HURRY (WILL MARK BRAINLIEST)
What happens when the sound waves released by a bat hit an object?
The sound waves are diffused.
The sound waves are reflected.
The sound waves are refracted.
The sound waves are absorbed,
Answer:
B.) The sound waves are reflected.
Explanation:
On edge,
i also answered so the other person could get the brainliest
Answer:
b
Explanation:
A sample of N2H4 has a mass of 25g. Identify the numerical quantity that is needed to convert the number of grams of N2H4 to the number of moles of N2H4. (You do not need to do the actual calculation.)
Answer:
Molecular Mass
Explanation:
It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.
(14g N * 2) + (1g H *4) = 32g / mol of N2H4
To get # of moles, divide the sample mass by the molecular mass
25g / 32g = 0.78125 moles
?
The group number tells the number of
Elements in the column
Number of valence electrons
O Number of energy levels
O Number of protons in the elements
Answer:
number of valence electrons
Explanation:
elements in the same group has same number of valence electrons
Calculate the number of moles of neon gas in 8.15 x 10^24 atoms of neon gas.
1.35 moles Ne
0.135 moles Ne
135 moles Ne
13.5 moles Ne
Answer:
13.5 moles of Ne
Explanation:
1 mole of any gas contains 6.02 x 10²³ atoms of gas
6.02 x 10²³ atoms of neon is equal to 1 mole of neon .
8.15 x 10²⁴ atoms of neon is equal to 1 x 8.15 x 10²⁴ / 6.02 x 10²³ moles
= 8.15 x 10²⁴ / 6.02 x 10²³ mole o neon
= 13.5 moles of Ne .
HELP ME ASAP PLEASE IDK THIS
Answer:
cExplanation:
A piece of gold has a mass of 21.7 kg and a volume of 5.78 cm3 . What is the density of gold? (Convert kgg)
Answer:
The answer is 3754.33 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question
mass = 21.7 kg = 21700 g
volume = 5.78 cm³
We have
[tex]density = \frac{21700}{5.78} \\ = 3754.3252...[/tex]
We have the final answer as
3754.33 g/cm³Hope this helps you
All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down an object, what is most likely true about the surface the object is moving on? The surface is dry. The surface is rough. The surface is uneven. The surface is smooth.
The question is incomplete, the complete question is;
All surfaces have texture, which means it affects how things move over it. When it takes a long time for friction to slow down and object, what is MOST LIKELY true about the surface the object is moving on? (A) The surface is dry (B) The surface is rough (C) The surface is uneven (D) The surface is smooth
Answer:
(D) The surface is smooth
Explanation:
Friction exists because of relative motion between two surfaces in contact with each other. However the magnitude of friction depends on how rough or smooth the surface is.
For smooth surfaces, there is little or no resistance to motion as objects move over the surface. Hence objects take a longer time to slow down on a smooth surface due to very little friction.
On a rough surface, objects tend to slow down relatively quickly. Hence, less resistance to motion on a smooth surface makes an object to take a longer time to slow down on a smooth surface than on a rough surface.
Answer: D
Explanation: Because if the surface is smooth it causes it to be more even for it to be able to cause Friction
if you find this helpful, Your welcome, if not, sorry.
Why can two water molecules stick to each other?
Determine the mass of 31.4 moles of Sodium.
Answer:
721.9 grams
I hope this helps!
Joe bought a roll of gray duct tape containing 5400 inches. If there are 5280 feet in a mile, how
many miles long is Joe's roll of duct tape?
Answer:
STANDARD: 0.085 mi, 450 ft, or 150 yds
METRIC: 0.137 km, 137.16 m, or 13716 cm
Explanation:
4. Advection fog forms when warm moist air comes in from the Pacific Ocean and
blows over the cold California current.
A.True
B.False
Answer:
A, True
Explanation:
Through which material does light move fastest?
Answer:
Explain that unlike sound, light waves travel fastest through a vacuum and air, and slower through other materials such as glass or water.
Explanation:
Hope this helped.
Answer:
empty space
Explanation:
What is the volume of a weather balloon that has 39 grams of helium with a density 0.017 g/mL?
Answer:
The answer is 235.29 mLExplanation:
The volume of a substance when given the density and mass can be found by using the formula
[tex]volume = \frac{mass}{density} \\ [/tex]
From the question.
density = 0.017 g/mL
mass = 4 g
We have
[tex]volume = \frac{4}{0.017} \\ = 235.2941176...[/tex]
We have the final answer as
235.29 mLHope this helps you