Answer:
The controlled variable of an experiment is the one thing that stays the same in an experiment.
Explanation:
An example would be : if I have two pennies, both dunked in water, but than I change one to be dunked in vinegar, the one dunked in water still is the constant or the controlled variable.
Consider the reaction.
2Pb(s)+O2(g)⟶2PbO(s)
An excess of oxygen reacts with 451.4 g of lead, forming 386.5 g of lead(II) oxide. Calculate the percent yield of the reaction.
Answer:837.9
Explanation:add those 2 numbers
When a sample of iron ore of mass 2.016 g is treated with 50.0 mL of hydrochloric acid, the iron dissolves in the acid to form a solution of . The solution is diluted to 100.0 mL and the concentration of ions is determined by spectrometry to be . What is the mass percentage of iron in the ore
Sometimes people have to cry out all their tears, to make room for a heart full of smiles.
True. I am always sad but my heart is always happy cuz it knows there are good things ahead
Where is groundwater stored?
Answer:
Answer Below! : )
Explanation:
Groundwater is stored in the tiny open spaces between rock and sand, soil, and gravel. How well loosely arranged rock (such as sand and gravel) holds water depends on the size of the rock particles.
Hope this helps! : )
Answer:
Underground brainliest plz
Explanation:
Why is volume measured with different units?
Answer:
The volume of an object can be calculated by multiplying its length, width and height. Further, depending on the shape of the object, its volume changes.
Explanation:
Hope this helps
Is a compound a mixture or a pure substance
Answer:
A compound is a pure substance.
How many molecules are in 8.27 mol of SiH,?
Answer:
from,
moles,n = number of particles, N
Avogadro constant
N = 8.27 * 6.022×10^23
N = 4.98 × 10^ 24particles.
In 8.27 moles of SiH, there are
4.98 × 10^24particles.
Aluminium sulphate is organic or inorganic compound
Answer:
Aluminium sulphate is an inorganic compound.
A solution is prepared by diluting 6.0 mL of a 7.6 x 10-4 g/mL solution to a total volume
of 10.0 mL. Calculate the concentration of the dilute solution.
Answer:
4.56 X 10^ -4 g/mL
Explanation:
A solution is prepared by diluting 6.0 mL of a 7.6 x 10-4 g/mL solution to a total volume of 10.0 mL. Calculate the concentration of the dilute solution.
(7.6 X10^-4 gm/m L) x( 6.0 m L ) = 45.6 X 10^-4 g
this is dissolved )in 10 m L=45.6 X 10^-4 g/ 10
4.56 X 10^ -4 g/mL
check
6/10 =0.6
4.56/7.6 = o.,6
Please answer question (e)
Answer:
here is no question (e).............
What would you name this molecule?
Answer:
H2O is the name of this molecule and it is water
How many mL of 1.76 M sodium hydroxide solution (strong base) must be added to 0.75
Macetic acid to make 683 mLa pH 49 buffer? (pka of acetic acid is 4.76)
Answer: Special care is required to prepare a solution of sodium hydroxide or NaOH in water because considerable heat is liberated by the exothermic reaction. The solution may splatter or boil. Here is how to make a sodium hydroxide solution safely, along with recipes for several common concentrations of NaOH solution.
Explanation:
Hope this helps!
What is difinition of chemistry
What method would you use to separate sand from gasoline?
Answer:
Filtration (The process of separating liquids and solids)
Explanation:
Filtration works best when the solute isn't dissolved in the solvent. Basically like how you can filter dirt or sand from water. The opposite of this would be if water and sugar where mixed together you cannot unmix this duo with filtration but with the example given you can use the process of filtration to rid the gasoline of sand.
What would happen if there were no gravity anywhere in the universe?
Objects would no longer be drawn toward each other, because there would be no sloping surface for them to fall down. Instead, they would fly off in whatever direction gravity was keeping them from going.
Answer:
All items in the universe, humans, objects, and the planets, would be floating around. Everything would become weightless.
What is the sum of the atomic numbers of each element present in the reactants of the given formula?
2 NH3 + H2SO4 → (NH4)2SO4
Answer:
25
Explanation: They all add up to 25 Atoms
The atomic number of nitrogen is 7 and that of oxygen is 8. Atomic number of hydrogen is one and the atomic number of sulphur is 16. Then, the sum of atomic numbers of each element present in the reactants of the given formula is 32.
What is atomic number ?The atomic number of an atom is the number of electrons in its neutral state. This number is equal to the number of protons also. The modern periodic table classify all elements based on their atomic numbers.
The sum of number of protons and neutrons of an element is called its mass number. For the given formula, the elements present are H, O, N and S.
atomic number of H = 1
atomic numebr of N = 7
atomic number of O =8
atomic number of S = 16.
Then ,sum of atomic number s= 1 + 7 + 8 + 16 = 32.
Therefore, the sum of the atomic numbers of each element present in the reactants of the given formula is 32.
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Electronegativity is a chemical property which describes how well an atom can attract an electron to itself. Values for electronegativity run from 0 to 4. The difference in electronegativity (ΔEN) is used to predict whether a bond between atoms will be ionic or covalent. It can also be used to predict if the resulting molecule will be polar or nonpolar.
If a bond was made between the two atoms shown below, would the bond be (1) covalent, i.e. ΔEN = ≤ 0.4, (2) polar covalent i.e. ΔEN > 0.4 and ≤2.0, or (3) ionic, i.e. ΔEN > 2.0? Enter 1 for covalent, 2 for polar covalent, 3 for ionic.
protactinium, francium
#protactinium
It lies in 7th period having Z=91The outer electronic configuration is 6d^17s^2
d-block element(transition)So it will form polar covalent bond (2)
#Francium
Z=87Outer electronic configuration 7s^1
s-block elementIt will form ionic bond (3)
Hydrocarbons are molecules that consist entirely of carbon and hydrogen atoms and are classified by their bond structure.
a. True
b. False
Answer:
true
Explanation:
hydrogen and carbon make hydrocarbons
Which atom would you expect to have a larger atomic
radius—francium or tennessine?
Answer:
Francium bc it has the largest atomic radius
Francium has the greatest atomic radius. Despite being a highly radioactive metal with a short half-life, francium has little environmental impact.
What is francium?Francium is a chemical element with the atomic number 87 and the symbol Fr. Francium-223, its most stable isotope, has a half-life of only 22 minutes, making it extremely radioactive. It is the second-most electropositive element and the second-rarest naturally occurring element, trailing only caesium.Francium has been used to study atomic structure in addition to being used in chemistry and research. It is used in the diagnosis and treatment of cancer. It is also used in a number of spectroscopic experiments. Despite being a highly radioactive metal with a short half-life, francium has little environmental impact. Francium is created by bombarding radium with neutrons in a nuclear reactor. It is also possible to create it by bombarding thorium with protons.To learn more about francium refer to:
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b. How does government funding affect scientific progress? (1 point)
Answer:
29 percent of federal R&D money goes to universities, 29 percent goes to industry, and another 29 percent goes to researchers who work directly for federal agencies. About 10 percent goes to federally funded labs operated by private contractors.
Answer:
Explanation:
Funding from the government greatly affects the scientific research as a research can take number of years to complete. During this time period lot of financial support is required as there might be lot of expensive chemicals or substance that the scientist requires for his research.
What physical and chemical properties would an antique dealer use to determine the substance that makes up a
piece of jewelry?
Answer:
Characteristics such as melting point, boiling point, density, solubility, color, odor, etc. are physical properties. Properties that describe how a substance changes identity to produce a new substance are chemical properties. ... Physical and chemical properties can be used to classify a substance as ionic or molecular.
calculate the mass in grams of two cubic inches (2.00 in³)" of gold. density of gold =19.3 g cm-.³
Taking into account the definition of density, the mass of two cubic inches (2.00 in³) of gold is 632.54 grams.
But first you must know the definition of density. Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.
In other words, density is a scalar quantity referring to the amount of mass in a given volume of a substance, that is, it shows the relationship between the weight (mass) of a substance and the volume it occupies.
Then, the expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:
[tex]density=\frac{mass}{volume}[/tex]
In this case, you know that:
Density= 19.3 g/cm³ Volume= 2 in³= 32.7741 cm³ (being 1 in³= 16.3871 cm³)Replacing in the definition of density:
[tex]19.3\frac{g}{cm^{3} } =\frac{mass}{32.7741 cm^{3} }[/tex]
Solving:
mass= 19.3 [tex]\frac{g}{cm^{3} }[/tex]× 32.7741 cm³
mass= 632.54 g
In summary, the mass of two cubic inches (2.00 in³) of gold is 632.54 grams.
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Three rocks are rolling down a hill at the same speed. Rock 1 has a mass of 1 kg1 kg; rock 2 has a mass of 1.5 kg1.5 kg, and rock 3 has a mass of 3 kg3 kg. Which rock has the most kinetic energy?
Answer: The first one has the most kinetic energy. Why? traveling with the slowest speed comes with the faster stop withholding more energy in the stone
Explanation:
Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?(1 point)
Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.
Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.
In acetylene each carbon atom share one pair of electrons with hydrogen atom and three pairs with the other carbon atom.
Carbon atom has four electrons its outermost shell it means that it needs four electrons to become stable. In acetylene, two carbon atoms covalently bonded three pairs of electron with each other and the one remaining pair is covalently bonded with two hydrogen atoms.
In this way the carbon as well as hydrogen atoms get stability so we can conclude that in acetylene each carbon atom share one pair of electrons with hydrogen atom and three pairs with the other carbon atom.
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In C2H2, each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.
Acetylene has the molecular formula C2H2. We must recall that carbon is a member of group 14 and it is always tetravalent in all its compounds. Hydrogen is always univalent in its compounds except in hydrides.
Since carbon is always tetravalent and hydrogen is univalent,each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom in C2H2.
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What are the law of 10 in energy Transfer
Answer:
When the energy is passed on from one trophic level to another, only 10 percent of the energy is passed on to the next trophic level.
Explanation:
Which has more calories: table sugar or aspartame?
Answer:
Aspartame produces 4 kilocalories of energy per gram when metabolized, sucrose (table sugar) produces 3.9 kilocalories. However, aspartame is approximately 200 times sweeter than sucrose, so it is consumed in much smaller doses.
Explanation:
Answer is Aspartame.
Butanoic acid + 2 propanol
Answer:
Butanoic acid and 2-propanol reacts to form isopropyl butyrate.
Explanation:
brainliest plz
MASTERING CONCEPTS
31. List three examples of substances. Explain why each
is a substance.
Answer:
vc
Explanation:
cvcv
PLZ ANSWER ASAP CHEMISTRY LAB REPORT
I am doing an investigation where I simply throw a piece of paper that has been lit on fire, into a glass bottle/jar, and then throwing a hard boiled egg in the jar. Asides the outcome, equations, or whatnot with all that Chemistry stuff, I want to know:
What is the constant and what is variable?
*Thank you to anybody whom can answer, but please, please, please, give me the right answers. These labs are worst the most of my grade and I already have a D- in Chemistry.
Answer:
welp to bad got nothing for you ezcecect good luck bye btw its always the one you think its not
Explanation:
dugg
Materials Visible Uniform Not Visible Non- Uniform State of Matter 1. Sugar and water 2. Oil and water 3. Vinegar and water 4. Salt and pepper 5. leaf and water
Answer:
1. Uniform, non visible
2. Visible, non uniform
3. Uniform, non visible
4. Visible, non uniform
5. Visible, non uniform
Explanation:
A heterogeneous mixture is simply any mixture that is not uniform in composition — it's a non-uniform mixture of smaller constituent parts. By contrast, a mixture that is uniform in composition is a homogenous mixture
visible state of matter is when you can easily difference two components of a mixture
non visible is when the state of the matter in the substance is not visible to the eye, it can't be differentiated