Mendeleev arranged the elements in the periodic table on the basis of atomic masses and stated the behavior of the elements in a periodic law. The periodic law is when elements arranged by the atomic masses they exhibit the presence of similar properties. Mendeleev focused on the chemical properties of the elements and Meyer focused on the physical properties of the elements. The change in the periodic table is that the elements are now arranged in the order of their atomic numbers instead of their atomic masses.
Energy pyramid worksheet
Pls help
Answer:
From top to bottom Jaguar, Toucan, Butterfly, and Hibiscus flower
Explanation:
Jaguars at the top because they eat toucans, Toucans eat butterflies, and butterflies eat hibiscus flower
Groups of atoms repeat to make up a substance?
True
False
Answer:
ITS TRUE!!!!!
what are the two components of a solution
28)
What is a molecule made from joining together small molecules called monomers?
A)
amino acid
B)
glucose molecule
nucleotide
D)
polymer
Answer:
D [polymers]
Explanation:
The joining of monomers (small molecules) is polymerization.
Explain how the copper could be in the lake sample near the picnic area but not have been detected by this test.
Answer:
May be the instrument is incorrect or may be error in it.
Explanation:
The copper have not been detected by this test because the test may be not for the detection of copper, may be it is used for identification of another minerals. If there is copper in the lake sample but can't be detected in the test so it means that the instrument which is used for detection is not the right one or having error in that instrument. Every mineral has a specific type of instrument that detect its presence, if we use incorrect instrument for the mineral then we can't detect the presence of that specific mineral.
On a summer day in Breckenridge, Colorado, the atmospheric pressure is 525 mm Hg. What is this air pressure in West Chester, Pennsylvania as it relates to the pressure in Colorado?
a. The same as in Colorado
b. Lower than in Colorado
c. Higher than in Colorado
d. There is not enough information to tell.
Answer:
Option B
Explanation:
The atmospheric pressure in West Chester, Pennsylvania is lower than the pressure on any summer day in Breckenridge, Colorado
Colorado is 1.6 kilometers above sea level while Pennsylvania is 0.33 kilometers above sea level.
The higher a place is above sea level, the higher is the air pressure.
Hence, option B is correct
92.12 kJ of heat is required to convert 58.40 g of gold from liquid to gas phase. What is the heat of vaporization of gold in J/g?
Answer:
The heat of vaporization of the gold sample is 1577.397 joules per gram.
Explanation:
The latent heat of vaporization of gold ([tex]h_{v}[/tex]), in kilojoules per gram, is the heat required by a unit mass of gold to transform the material from liquid to gas:
[tex]h_{v} = \frac{E}{m}[/tex] (1)
Where:
[tex]E[/tex] - Energy required for vaporization, in joules.
[tex]m[/tex] - Mass, in grams.
If we know that [tex]E = 92120\,J[/tex] and [tex]m = 58.40\,g[/tex], then the heat of vaporization of the gold sample is:
[tex]h_{v} = \frac{E}{m}[/tex]
[tex]h_{v} = 1577.397\,\frac{J}{g}[/tex]
The heat of vaporization of the gold sample is 1577.397 joules per gram.
this is due in five mintues please help
Answer:
5
Explanation:
Na, N, O, O, O
What does the first ionization energy represent?
Someone plz help me
Answer:
maybe falling
Explanation:
Air is a force so its probably pushing down the object then making it fall
I think all objects? Not entirely sure.
2 SO3 (g) + Heat <-----> 2 SO2 (g) + O2 (g)
For the above reaction, what will happen to the concentration of SO2 if the pressure is increased? Explain your answer
Answer:
The concentration of SO₂ will decreases
Explanation:
As you can see in the reaction
2 moles of gas ⇆ 3 moles of gas
Based on Le Châtelier's principle, a change doing in a system will produce that the system reacts in order to counteract the change made.
If the pressure is increased, the system will shift to the left in order to produce less moles of gas and decrease, thus, the pressure.
As the system shift to the left, the concentration of SO₂ will decreases
Why are different detergents made for cleaning different surfaces and how their chemical structure/composition affects this?
Answer: This is because of the different chemical composition of the types of detergents affects their cleansing actions.
Explanation:
Detergent means any substance which has the ability to clean an object. This includes soaps, soap powers and dish washing liquids as well as water. Detergents fall into two main types
--> Soapy detergents and
--> Soapless detergents
Soapy detergents are sodium salts of fatty acids. They are saponification products of fats and oils. In the chemical composition, each molecule of soap possesses a long hydrocarbon chain attached to an ionic head. The hydrocarbon tail is hydrophobic, so it is insoluble in water but soluble in oil and organic solvents. The ionic head is hydrophilic, so it is soluble in water. Due to this dual nature, when is dissolved in water, the soap molecule forms spherical clusters called MICELLES( hydrocarbon tails points inward and ionic heads point outward). Repulsion between the similarly charged ionic heads keeps the micelles apart. This property helps the soapy detergent to lift grease from grease coated fabrics when applied to it.
While the chemical properties of the Soapless detergents has a hydrophobic tail and a hydrophilic head. The hydrophobic tail is either a long chain hydrocarbon or a benzene ring with a long alkyl group attached. The hydrophilic head, unlike the Soapy detergents, can be positively or negatively charged or even neutral. These chemical properties makes it to have a more favourable and wider application than soapy detergent.it is suitable for washing acid - sensitive fabrics and for breaking up oil slicks.
identify the limiting reactant when 7.28 grams of magnesium oxide reacts with 4.50 grams of aluminum to make magnesium and aluminum oxide? i need a typed answer a link wont work
Answer:
the limiting reactant is aluminum
Explanation:
In a food chain, energy does NOT flow directly from - F producer to decomposer G producer to consumer H consumer to decomposer J consumer to producer
Answer:
producer to decomposer
Explanation:
This is because in a food chain , energy flow from one trophic level to another. The producer which include plants are the source of energy which they manufacture good in the presence of light energy from sun. Energy flow directly from the producer to the primary consumer which are heterotrophs that feed on plants. Energy flow from consumer to decomposer after the consumer died and it is decayed.
Magnesium oxide (mgo) has the rock salt crystal structure and a density of 3.58 g/cm3. the atomic weights of magnesium and oxygen are 24.31 g/mol and 16.00 g/mol, respectively. (a) determine the unit cell edge length.
Answer:
(a) The unit cell edge length 0.421 nm
Explanation:
Lets calculate -:
Given -
density = [tex]3.58g/cm^3[/tex]
Molecular weight of MgO = 24.31 +16
[tex]40.13 g/mole[/tex]
Avagadro number = [tex]6.022\times10^2^3[/tex]
In rock salt structure , there are four anions and four cations , hence Z=4 (Number of formula per unit cell)
Now, using the formula -
[tex]d=\frac{ZM}{N_Aa^3}[/tex]
[tex]a=[\frac{ZM}{N_Ad}]]^\frac{1}{3}[/tex]
Now, putting the given values
[tex]a=\frac{4\times40.13g/mole}{6.022\times10^2^3\times(3.58g/cm^3)}[/tex]
[tex]4.21\times10^-^8 cm[/tex]
= 0.421 nm
Hence , the unit cell edge length = 0.421 nm
The unit cell edge length of magnesium oxide (MgO) is equal to 0.421 nanometer.
Given the following data:
Density = 3.58 [tex]g/cm^3[/tex]Atomic weight of magnesium = 24.31 g/mol.Atomic weight of oxygen = 16.00 g/mol.Scientific data:
Avogadro's number = [tex]6.02 \times 10^{23}[/tex]Z for FCC = 4Molar mass of magnesium oxide (MgO) = [tex]24.31 + 16 = 40.31 \;g/mol.[/tex]To determine the unit cell edge length:
Mathematically, the unit cell edge length for a face-centered cubic (FCC) structure is given by the formula:
[tex]a=\sqrt[3]{\frac{ZM}{\rho N_A} }[/tex]
Where:
Z is the number of atoms per unit cell.[tex]\rho[/tex] is the density.M is the molar mass.[tex]N_A[/tex] is the Avogadro constant.Substituting the given parameters into the formula, we have;
[tex]a=\sqrt[3]{\frac{4 \; \times \;40.31}{3.58\; \times \;6.02 \times 10^{23}} }\\\\a=\sqrt[3]{\frac{161.24}{2.16 \times 10^{24}}}\\\\a=\sqrt[3]{7.47 \times 10^{-23}} \\\\a=4.21 \times 10^{-8}\;meter[/tex]
Note: [tex]1 \;nanometer = 1 \times 10^{-9} \;meter[/tex]
a = 0.421 nanometer.
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50 POINTS
Answer:
a
Explanation:
i am wrong haha
Answer:
are u out of time ?
Explanation:
3. Define the following:
a. electromagnetic radiation
b. wavelength
c. frequency
d. quantum
e. photon
Mg(s) + HCl (l) --> H2 (g) +MgCl2 (s) A student conducted an experiment with 2g of magnesium and 3 mL of 6M hydrochloric acid. Equal volumes (3mL) of hydrochloric acid and magnesium strips (2g) were put into each tube. What are the reactants in this reaction?
Answer: Do you have an image so I can solve it?
True or False - Every gas has a unique set of spectral lines that help identify the gas.
Every gas has a unique set of spectral lines that help identify the gas is a true statement.
Why do elements have different spectral lines?A spectral line is a dark or bright line that appears in an otherwise uniform and continuous spectrum as a result of light being emitted or absorbed at a narrow frequency range as opposed to frequencies close by.
Note that a lot of element has a distinct line spectrum, which is known as the "fingerprint" of that element. Because each element has a different amount of electrons and hence a diverse range of energy levels, each one's spectra are distinctive.
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How many molecules are in
6.0 moles of methane (CH4)?
Let's begin by setting up our equation.
What belongs in the green box?
6.0 moles CHA
A. 1 mole CH4
B. 6.02 x 1023 molecules CH4
22 Determine the molar mass of an unknown gas that has a volume of 72.5 mL at a temperature of 68C, and a pressure of 0.980 atm and a mass of 0.207 g.
Answer:
81.5g/mol
Explanation:
Molar mass is the ratio between mass of a substance (In this case, 0.207g) and moles presents in this mass.
To solve this question we must find the moles of the gas in order to obtain the molar mass using:
PV = nRT
PV / RT = n
Where P is pressure = 0.980atm
V is volume in Liters = 0.0725L
R is gas constant = 0.082atmL/molK
T is absolute temperature = 68°C + 273.15 = 341.15K
0.980atm*0.0725L / 0.082atmL/molK*341.15K = n
2.54x10⁻³ moles = n
Thus, the molar mass of the gas is:
0.207g / 2.54x10⁻³ moles
81.5g/molNitrogen is used to keep food frozen during transportation.
Which properties make it suitable for this?
Answer:
Gaseous nitrogen has unique chemical and physical properties that make it suitable for use in food processing. Nitrogen is inert which means it will not react with prepared food materials, which can alter their aromas or flavors. Also, gaseous nitrogen will effectively displace oxygen minimizing oxidation and the growth of microorganisms that cause foods to lose their freshness and deteriorate faster.
Explanation:
Source: https://www.generon.com/using-nitrogen-gas-in-food-packaging/
"Because it deflects oxygen, nitrogen is just a common gas for food packing." Because oxygen will carry moisture, this is critical. Bacteria use oxygen to grow and survive on organic matter. Bacteria find it much harder to develop while as much oxygen as possible is removed.
What is food packing?Food packaging is the process of packaging food. A package provides security, resistance to manipulation, and particular physical, chemical, and even biological requirements. Food packaging may include a nutrition label and other information about the product being sold.
What is bacteria?Bacteria are commonly found, mostly free-living organisms with one biological cell. They belong to the prokaryotic organisms category. Bacteria, which have been typically a few micrometers long, were one of the first living species to originate on Earth and may be found in practically every ecosystem.
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SO2 +
Li2Se →
SSe2 +
Li20
Type of Reaction:
We want to take inventory of the right and left side
Right: S=1 O = 2 Li = 2 Se= 1
Left: S= 1 Se=2 Li= 2 O=1
Lets balance out each side because we see we are off by 1 oxygen on the left
Add a coefficient of 2 on the Li2O
Add a coefficient of 2 on the right Li2Se
Now we have So2+ 2Li2Se ---> SSe2+ 2Li2O
or
The equation is already balanced, assuming that there is supposed to be a yields symbol between 2Li2Se and SSe2.
To find out whether or not this equation is balanced, make a little T-chart with the left side of the equation on one side and the left on the other. Next to each element, write down the amount they start off with and make changes as you add coefficients.
Hope this helps!
CH3 CH3 CH3-CH2-CH=CH-CH-CH-C-CH-CH3 CH3 COMO SE LLAMA?
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Answer:
it is b
Explanation:
mid ocean ridge diverges meaning it moving in two different direction horizontally - left to right
TRUE OR FALSE?
It is not possible for wind can push an air parcel even higher in the troposphere, causing the parcel to cool and lose more energy, which will lead to more rainfall.
Answer:
The more water vapor in the air parcel, the more condensation can occur, and therefore, more rain. ... The air parcel then loses more energy, causing more rainfall. Wind pushes air parcels even higher in the troposphere, where it is colder. The air parcels will then lose more energy and more rain can happen.
I think is FALSE, is that right?
2 questions. will give brainliest if i can figure out how
What happens to the electrons of a reducing agent during a reaction?
a.Electrons are gained
b.Electrons are lost
c.Electrons are held
d.Electrons are doubled
When is a substance reduced during an oxidation reduction reaction?
a.After one substance is oxidized
b.Before one substance is oxidized
c.Same time as one substance is being oxidized
d.Only oxidation occurs
1= b. electrons are lost
2= a. after one substance is oxidized
What is the term for the limited recyclable life of certain materials? o single-stream recycling o closed-loop recycling O dual-stream recycling downcycling
Answer:
There are three main types of recycling: primary, secondary, and tertiary.Single-stream recycling is a system in which all recyclables, including newspaper, cardboard, plastic, aluminum, junk mail, etc., are placed in a single bin or cart for recycling. ... While collections costs are lower with a single stream system, processing costs are much higher.
Explanation:
Hope it helps u
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Characteristics that are used to help identify an object are called
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