Answer:
1) The volume occupied by an atom is composed of mainly empty space
2) Atoms have a very small, relatively dense, central nucleus that is positively charged
3) The region around the nucleus of an atom are orbited by negatively charged electrons in a the same fashion planets orbit around the Sun.
Explanation:
The selection of gold for the gold foil experiment was due to its ability to be rolled into extremely thin sheets such that it was expected for alpha particle to perforate or pass through the foil.
Which best describes the importance of the microscope to the development of the cell theory?
Answer:
The answer is "all the cells are too small, which is not seen by the naked eye, that's why we use a microscope to see it".
Explanation:
In the given question the choices were missing so, we define the correct answer only.
Cells are the essential building blocks of all living entities. There will be trillions of cells within the body. They construct a body shape, absorb nutrients, transform them into energy, and conduct specialized features.
It provides stability and guidance, encourages mitotic cell development, encourages active and passive transfer, generates energy, induces metabolic processes, and contraceptive support.
What happens during an alpha decay?
Answer:
Alpha decay is a type of radioactive disintegration in which unstable atomic nucleus releases a helium nucleus or alpha particle and transform into a different element. The new element formed will be reduced by four and the atomic number will be reduced by two.
Example of alpha decay is: Uranium 238 transform into Thorium 234 with the emission of an alpha particle.
can you catch coronavirus from F.A.R.Ts?
Answer:
No
Explanation:
Droplets or aerosols. When an infected person coughs, sneezes, or talks, droplets or tiny particles called aerosols carry the virus into the air from their nose or mouth. Anyone who is within 6 feet of that person can breathe it into their lungs.
Airborne transmission. Research shows that the virus can live in the air for up to 3 hours. It can get into your lungs if someone who has it breathes out and you breathe that air in.
Surface transmission. Another way to catch the new coronavirus is when you touch surfaces that someone who has the virus has coughed or sneezed on. You may touch a countertop or doorknob that's contaminated and then touch your nose, mouth, or eyes. The virus can live on surfaces like plastic and stainless steel for 2 to 3 days. To stop it, clean and disinfect all counters, knobs, and other surfaces you and your family touch several times a day.
Fecal-oral. Studies also suggest that virus particles can be found in infected people's poop. But experts aren't sure whether the infection can spread through contact with an infected person's stool. If that person uses the bathroom and doesn't wash their hands, they could infect things and people that they touch.
Three determinations were made of the following percentage of oxygen in mercuric oxide. The results were 7.40%, 7.43%, and 7.35%. What was the average percentage?
Which of the following sequences describes how a four-stroke engine cycle
powers the engine?
Answer: Air and fuel intake, compression and ignition, combustion and expansion, exhaust
Explanation:
The primary function of a scuba regulator is to: Reduce high-pressure gas in the scuba cylinder to a more breathable intermediate pressure. Reduce high-pressure gas in the scuba cylinder to ambient (surrounding) pressure. Provide a diver with a continuous flow of oxygenated air. None of the above.
Answer:
Reduce high-pressure gas in the scuba cylinder to ambient (surrounding) pressure.
Explanation:
The primary function of a scuba regulator would be to reduce high-pressure gas in the scuba cylinder to ambient pressure.
A scuba regulator is a structure found attached to the scuba cylinder usually carried by scuba divers. The structure regulates the pressure of the breathing gas in the cylinder to a safe level before the gas becomes available for the breathing process of divers.
Usually, the gas in a scuba cylinder is at a high level. Hence, what the regulator does is to bring it down to a level that would be safe for the breathing of the diver.
Express each of the following in standard form.
3.6 x 101
6.452 x 102
8.77 x 10-1
6.4 x 10-3
Answer:3.6 x 101 or 8.77 x 10-1
Perform the forlowing
mathematical operation, and
report the answer to the correct
number of significant figures.
4568/13 = [?]
Answer:
[tex]\large \boxed{350}[/tex]
Explanation:
In multiplication and division problems, the answer can have no more significant figures than the number with the fewest significant figures.
My calculator gives the result:
[tex]\dfrac{4568}{13} = 351.3846154[/tex]
4658 has four significant figures.
13 has two significant figures.
You must round to two significant figures.
That is, you drop all the digits to the right of the 5 — the red line in Fig. 1 below. You are rounding to the nearest ten.
To round a number to the nearest ten, you look at the number in the ones place (1). See Fig. 2.
If the number to be dropped — the digit in the ones place — is less than 5, you drop the digit in the ones place (Fig. 3). It becomes a zero.
The number in the tens place is a trailing zero. It is not significant.
[tex]\text{The quotient of $\dfrac{4658}{13}$ is $\large \boxed{\mathbf{350}}$}[/tex]
which state of matter is Na OH(s)
Explanation:
SOLID
Sodium hydroxide exists in the solid phase at room temperature. You would find it in the lab as hemispherical white solid pellets. The phase of a substance depends on temperature and pressure. As you heat a solid, it will melt and change to the liquid phase.
Questions
1 Explain why a solid expands when it is heated.
2 Explain how the liquid in a thermometer changes so that it can be used to
measure a temperature.
3 Use particle theory to explain why solids and liquids cannot be compressed
(squashed into a smaller volume).
4 Use particle theory to explain why liquids and gases can flow.
Answer:
answer of question 1 is
Explanation:
solids are denser than liquid and gases because solid particles are closely packed and do not have any empty spaces between their particels so when solid will heated its particles will spread and there will have more spaces between them so a solid expand on heating.
5. What distinguishes the noble gases from other elements in the main group?
How does this contribute to the tendency for the various elements to react
with each other?
Answer:
Noble gases are the least reactive of all known elements. Their outer energy levels are full because they each have eight valence electrons. ... As a result, noble gases cannot become more stable by reacting with other elements and gaining or losing valence electrons.
Explanation:
Noble gases have complete valence shells so they do not participate in the reactions while the other elements in the main group have incomplete valence shells so they participate in the reaction to complete it.
What are noble gases?Noble gases can be described as the six elements that belong to the 18th group of the modern periodic table. The elements of group 18 are Helium, Neon, Argon, Krypton, Xenon, and Radon.
Under normal temperature and pressure conditions, all noble gases exist in the gaseous state and exhibit low chemical reactivity hence they are also referred to as inert gas. All noble gases possess stable electronic configurations because their valence shell is fully filled.
Noble gases are generally found as mono-atomic gases. The general electronic configuration group 18 elements can be written as ‘ns²np⁶’ where n is the principal quantum number.
Therefore, the reactivity of the noble gases can be distinguished from other elements in the main group.
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HELP PLEASE NAME THESE COMPOUNDS topic of amines and amides please explain you steps so i can do the rest of the problems myself
The attachment shows the diagram of two molecules respectively;
The first molecule in the attachment is known as triethylamine,The functional group is amine Which is - CONH2
And there is a methyl group as an attachment, attached at the third(3) carbon atom,making the compound triethyamine.
The second molecule in the attachment is an example of a secondary amide.
The longest carbon chain is five which pentanamide.
The functional group is amide.
The compoud is named by replacing the suffix - ane in pentane (alkane) to the suffix - amide.
Making the compound pentanamide.
8.310x10^2 – 7.210x10^1
[?]x10^[?]
Answer:
[tex]7.589\times 10^{2}[/tex]
Explanation:
The expression can be solved mathematically as follows:
1) [tex]8.310\times 10^{2}-7.210\times 10^{1}[/tex] Given
2) [tex]8.310\times 10^{1+1} - 7.210\times 10^{1}[/tex] Definition of sum
3) [tex](8.310\times 10^{1})\times 10^{1}-7.210\times 10^{1}[/tex] [tex]a^{m+n} = a^{m}\cdot a^{n}[/tex]/Associative property
4) [tex](8.310\times 10^{1}-7.210)\times 10^{1}[/tex] Distributive property
5) [tex](83.100-7.210)\times 10^{1}[/tex] Multiplication
6) [tex]75.89\times 10^{1}[/tex] Subtraction.
7) [tex](7.589\times 10^{1})\times 10^{1}[/tex] Multiplication/Associative property
8) [tex]7.589\times (10^{1}\times 10^{1})[/tex] Associative property
9) [tex]7.589\times 10^{2}[/tex] [tex]a^{m+n} = a^{m}\cdot a^{n}[/tex]/Result
which of the following flouride has the highest lattice energy a)NaF b)KF c)CsF d)LiF
Answer:
The correct option is;
d) LiF
Explanation:
The Lattice energy of ionic compounds can be calculated using the modified Coulomb's law as follows;
[tex]U = \dfrac{k' \cdot Q_1\cdot Q_2}{r_0}[/tex]
Where;
Q₁ and Q₂ = The ionic charges
k' = A constant depending on the ionic and valence configuration
r₀ = The distance between the two nucleus
Given the four compounds each of the metallic ions are of the same group (group one) have the same (only one) valence electron, and are combined to the same ion (fluoride ion) such that Q₂, is the same for all compounds, the factor that will influence the lattice energy more will be the r₀
The sizes of the atoms Li, Na, K and Cs increases as arranged as such Li has the least r₀, and therefore LiF the least lattice energy
From chemistry test online, we have;
The lattice energy of LiF = -1045 kJ/mole
The lattice energy of NaF = -924 kJ/mole
The lattice energy of KF = -822 kJ/mole
The lattice energy of CsF = -737 kJ/mole.
Which are the physical properties of water
What is the molarity of a 50.0ml aqueous solution containing 10.0 grams of hydrogen peroxide H2O2
Molarity= No of moles of solute * 1000 / vol solution in ml
No of moles= Given mass / Molar mass
Given Mass of solute (H2O2)= 10g
Molar mass of H2O2=34gmol^-1
No of moles= 10/34= 0.294 moles
Volume of solution=50ml
Molarity = 0.294*1000 / 50
Molarity = 5.8M
Define freezing....... Correct and detailed answers will be marked as Brainliest.
The transformation of liquid into solid when it reaches when it's temperature is below freezing point.
Answer:
Freezing:
When liquid is converted to solid, the process is called freezing.
Conditions for freezing:
1) Temperature must be lowered.
2) The temperature should be below 0 degree centigrade.
Example:
The conversion of "liquid water" into "ice".
=> We can use a "freezer" to freeze things.
Di- Ethyl zinc is a chemical used in the library to protect books from worms, its composition is 53% Zinc, 38.9% Carbon, and 8.1% Hydrogen (At mass of Zn=65.4, C=12, H=1). Find the empirical formula of a compound
Answer:
ZnC4H10
Explanation:
The empirical formula of a compound refers to the formula that gives the simplest whole number ratio of each atoms of the elements in the compound.
The empirical formula is calculated thus:
The given percentages in the question represent the mass in grams of each element in the compound.
Zinc= 53%, C= 38.9%, H= 8.1% which represents 53g, 38.9g and 8.1g of each element respectively.
Molar Mass of Zn= 65.4 g/mol
Molar Mass of C= 12 g/mol
Molar Mass of H= 1 g/mol
Step 1: Divide the mass of each element by the molar mass given to convert to moles:
Zn= 53/65.4 = 0.81moles
C= 38.9/12 = 3.24moles
H= 8.1/1 = 8.1moles
Step 2: Divide each mole value by the smallest number of moles calculated, which is 0.81moles:
Zn= 0.81/0.81 = 1
C= 3.24/0.81 = 4
H= 8.1/0.81= 10
This is the mole ratio represented in the subscript of each element in the empirical formula:
That is, Zn (1) C (4) H (10)
Empirical formula= ZnC4H10
The melting points of ionic compounds _____
Explanation:
ionic compounds have high melting points
A student is reading the volume from a standard 50-mL buret identical to what you used in the lab. The bottom of the meniscus is exactly on the 20-mL line. What should she record as the correct volume
Answer:
20 mL
Explanation:
The student should record 20 mL as the correct volume.
The curved surface of a liquid that is usually observed in a buret is referred to as the meniscus. This meniscus is created as a result of the surface tension of the liquid against the walls of the buret. Hence, in order to avoid errors due to parallax, the bottom of the meniscus should be read and not the top.
Therefore, the correct volume that the student should record is 20 mL.
absorption of digested food takes place in the
Answer:
Explanation:
Absorption of digested food takes place in the small intestine.
Hope this helps
plz mark as brainliest!!!!!
Answer:
Absorption of digested food takes place in the small intestine.
Explanation:
Sulphur dioxide is a common pollutant from burning coal.State two effects caused by this pollutant and also write the chemical equation.
Heya!
Sulfur dioxide - ( SO2 )
Answer:
Sulfur dioxide is a common pollutant caused due to the burning of coal,Is very harmful for the environment and health.Effects:
Health effects-Sulfur dioxide effects the respiratory system which includes the functioning of lungs,respiratory track and causes infections,can also effect and irritate the eyes and causes aggravating conditions such as asthma and chronic bronchitis.As most sulfur dioxide air pollution comes from the burning of coal and oil in power plants. It is a emitted by trains, large ships and other diesel objects that burns alota sulfur fuel so this also effects the environment like plants and others as the air lacks oxygen ,but with more sulfur dioxide.Hope this helps!
Have a nice day!:)
What wavelength measures
A. Depth
B. Distance
C. Energy
D. Speed
E. Time
F. Volume
Answer:
Distance.
Explanation:
Wavelength (λ) can be defined as the distance between two successive crest or trough of a wave.
From the above definition, wavelength (λ) simply measures distance.
This can further be explained by obtaining the unit of measurement for wavelength (λ).
This can be illustrated below:
Wavelength is related velocity and frequency according to the following equation:
Velocity (v) = wavelength (λ) x frequency (f)
v = λf
λ = v/f
Velocity is measured in ms¯¹
Frequency is measured in hertz, Hz (s¯¹)
λ = v/f
λ = ms¯¹ / s¯¹
λ = m
We can see that wavelength is measured in metre (m) which is the same unit for measuring distance.
Therefore, wavelength measures distance.
In science class, Jake mixed water with differing amounts of an unknown liquid. After mixing the liquids, he heated 20 milliliters (ml) of each mixture and observed how quickly it boiled. The table shows his results.
According to the question, each mixture decrease the boiling point of the water.
What is boiling point ?Boiling temperature is defined as the temperature at which liquid change into a vapour at the atmospheric pressure at sea or ocean level.
For example the boiling temperature of water is 100 degree celcius.
Thus, each mixture decrease the boiling point of the water, option "A" is correct.
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What is atom economy? A. All of these B. The system that determines how much 1 mole of a pure element costs. C. The measure of how much of the reactants end up as products in a chemical reaction. D. The system of exchanging electrons that occurs in atoms.
Answer:
C
Explanation:
It's the amount of products you get compared to all the reactants you use. It's kind of like economy in that it's profit, and the higher the atom economy the more products/profit you have.
Answer:
C.) The measure of how much of the reactants end up as products in a chemical reaction.
Explanation:
I got it right on founders edtell.
WILL GIVE BRAINLIEST, Which of the following would have the greatest amount of surface area?
A. 1 cubic foot of watermelons
B. 1 cubic foot of matchbox cars
C. 1 cubic foot of loose sand
D. A 1 cubic foot block of concrete
Answer:
C. 1 cubic foot of loose sand
Explanation:
For many objects having equal volume , surface area will be maximum
of the object which has spherical shape .
But when a sphere is broken into tiny small spheres , total surface area of all the small spheres will be more than surface area of big sphere .
Hence among the given option , surface area of loose sand will have greatest surface area . Loose sand is equivalent to small spheres .
Answer:
the answer would be C 1 cubic foot of loose sand.
Draw the geometric, linkage, and ionization isomers for [CoCl5CN][CN].
Answer:
See explanation
Explanation:
The formation of isomers is common to octahedral complexes. Isomers are different compounds with the same molecular formula but different structural formulas. Isomers have different atom to atom connections. Werner's complexes can display; polymerization, ionization, linkage, geometric and optical isomerism among others.
Isomers of coordination compounds are not easily recognizable and not easily separable in the laboratory.
The geometric, linkage and ionization isomers of the complex given in the question are shown below.
One day, you decide to pop some popcorn. You put the bag in the microwave, but after a couple of minutes of cooking it is clear the popcorn is not popping. Why did this happen? What steps could you take to help locate the problem?
Iron and aluminum are examples of
Answer:
Iron and aluminum are both examples of metals that are used commonly in everyday life.
Give two examples of neutralization
Answer:examples for neutralization - treating indigestion,treatment for insect bites.hope it help you
Explanation:
