Answer:
3.48 g
Explanation:
Because its useful.
Can someone help, please...?
I really can't understand this...
2. This chart describes several characteristics of human civilizations.
(6.04)
Characteristics of Human Civilizations
Stable Food Supply
?
Developed Systems of Writing
Which phrase best completes this list?
A. Created militaries
B. Complex social structures
C. Use of fire for protection
D. Declining population
High exposure to mercury is indicated by a blood level above 10 mg/L. How many mercury atoms are in a liter of blood that contains 10 mg mercury?
Answer:
3.0x10¹⁹ atoms
Explanation:
First we convert 10 mg of mercury into grams:
10 mg / 1000 = 0.01 gThen we convert 0.01 g of mercury into moles, using its molar mass:
0.01 g ÷ 200.59 g/mol = 4.99x10⁻⁵ molThen we convert moles into number of atoms, using Avogadro's number:
4.99x10⁻⁵ mol * 6.023x10²³ atoms/mol = 3.0x10¹⁹ atomsWhich organ detects stimuli from the environment and is part of the nervous system?
Group of answer choices
A. eye
B. stomach
C. heart
D. lungs
It's the eye because it's the organ of sight
how is it proved that carbon is present in sugar?
Answer:
In all living organisms, in substances like carbohydrate, starch, urea etc. To prove sugar contains carbon, take a little amount of sugar in spoon and heat it gently till it melts and turned into yellowish color. On further heating it changes into brown colored mass and then black, which is charcoal.
Take a small bit of sugar on a spoon and slowly heat it until it melts and turns a yellowish tint to demonstrate that it contains carbon. As it continues to heat up, it transforms into charcoal, which is a black mass first.
What is Charcoal ?Strongly heating wood with little oxygen produces charcoal, a light black carbon residue that has been stripped of all water and volatile components.
Since the beginning of time, charcoal has been used for a wide variety of reasons, including art and healing, but its most significant usage has been as a metallurgical fuel. The typical fuel for a blacksmith's forge and other uses requiring high heat is charcoal.
Sugar breaks down into carbon and water when it is heated. Water is still a chemical, but it can't be heated
Thus, As it continues to heat up, it transforms into charcoal, which is a black mass first.
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Why is it important to know characteristics that matter undergoes in chemistry? How can we analyze the relationships between chemical and physical changes and properties?
Extension Questions: What is the study of Chemistry? Who are some of the important people who have contributed to the field? How do regular Americans interact with Chemistry around them?
How can we understand the historical development of the Periodic Table and apply its predictive power?
Extension Questions: Describe different chemical principles and systems. How does the layout of the periodic table allow you predict other element's properties? Consider all types and groups of elements.
Why is it important to know and understand the historical development of atomic theory?
Extension Questions: How does the atom relate to the elements of the periodic table? What are your most common models and how do they relate to the current atomic model? What theories don’t hold true today if any?
How do atoms combine to form ionic, covalent, and metallic bonds?
How can we write and balance chemical equations using the law of conservation of mass?
Answer:
Chemistry is important because everything you do is chemistry! Even your body is made of chemicals. Chemical reactions occur when you breathe, eat, or just sit there reading. All matter is made of chemicals, so the importance of chemistry is that it's the study of everything.
Excessive use of chemical fertilizer cause chemical pollution.How?
Explanation:
Chemical fertilizers raise crop yields, but their heavy usage has hardened the soil, diminished fertility, reinforced pesticides, contaminated air and water, and emitted greenhouse gases, posing health and environmental risks.
Pl help it’s for a grade and I can’t find it
Answer:
personally I think it's a but it could also be D.
But yeah personally I would say A
If you produce 10 g of water in the reaction from 20 g of O2 what is your percent yield? 2H2+O2>2H2O
Answer:
44.4%
Explanation:
The balanced chemical equation for the reaction is:
2 H₂(g) + O₂(g) → 2 H₂O(g)
According to the equation, 1 mol of O₂ produces 2 moles of water (H₂O). We convert the moles to grams by using the molecular weight (Mw) of each compound:
Mw(O₂) = 2 x 16 g/mol O = 32 g/mol
mass O₂ = 1 mol x 32 g/mol = 32 g O₂
Mw(H₂O) = (2 x 1 g/mol H) + 16 g/mol O = 18 g/mol
mass H₂O = 2 mol x 18 g/mol = 36 g H₂O
Thus, from 32 grams of O₂, 36 g of H₂O are produced (stoichiometric ratio= 36 g H₂O/32 g O₂). We calculate the amount of H₂O that would be produced from 20 grams of O₂ by multiplying the stoichiometric ratio by the mass of O₂, as follows:
36 g H₂O/32 g O₂ x 20 g O₂ = 22.5 g H₂O
The theoretical yield of H₂O is 22.5 g, and the actual amount produced is 10 g. So, we calculate the percent yield as follows:
Percent yield = actual yield/ theoretical yield x 100
= (10 g)/(22.5 g) x 100
= 44.4%
Please help this is due soon and I’ll mark you brainiest if you can help
Answer:
I think it's either A or D I'm not sure hope that I helped you.
Why does an ice cube melt when you hold it in your hand?
Your hand transfers temperature to the ice cube.
Heat from the ice cube is transferred to your hand.
Heat is transferred from your hand to the ice cube.
The ice cube radiates heat to your hand.
heat is transferred from your hand to the ice cube
Answer:
Heat is transferred from your hand to the ice cube.
How many grams of NaCl can be dissolved in 100 grams of water at 70°C? What is its concentration? (20 pts.)
Answer:
70 g NaCl at 20 °C Supersaturated.
how can water become more acidified than normal due to
atmospheric pollutants
Answer:
The water can become acidified than normal because all the pollution such as when carbon dioxide can dissolve in sea waters causing the water be polluted because of the bad air.
Explanation:
A wildfire destroys most of the plant life in a forest. What would most likely happen to the animals that lived in the forest?
Answer:
They would be pushed out and lose their homes
Explanation:
A wildfire destroys most of the plant life in a forest. Animals would be pushed out and lose their homes.
What is wildfire?An unplanned, uncontrolled, and unpredictable fire inside an area of flammable vegetation is known by several names, including wildfire, bushfire, bushfire, wildland fire, and rural fire. A wildfire may be more precisely referred to by the terms bushfire, desert fire, forest fire, hill fire, peatland fire, prairie fire, vegetable fire, or veld fire, depending on the kind of vegetation that is present.
Wildfires are separate from controlled and prescribed burning, which is a good human use of wildland fire, even though controlled burns have the potential to turn into wildfires. Wildfires likely started shortly after terrestrial plants first appeared, which occurred in the Silurian epoch 419 million years ago, according to fossil charcoal. A wildfire destroys most of the plant life in a forest. Animals would be pushed out and lose their homes.
Therefore, animals would be pushed out and lose their homes.
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plzzzz helppp i will cryy :(
Answer:
okay you need to find the synnomy
How are plate tectonics and the rock cycle connected
Answer:
All igneous rocks the basis of the rock cycle are formed by plate tectonics. ... The heat from the mantle that fuels plate tectonics causes both igneous and sedimentary rocks to be turned into metamorphic rocks. The metamorphic rocks can be eroded into sedimentary rocks are remelted back into igneous.
Explanation:
A tank contains helium gas at 585 mmHg, nitrogen gas at 0.76 atm, and neon at 940 torr. What is the total pressure
Answer:
2.77 atm
Explanation:
The total pressure of a mixture of gases is calculated as the addition of the partial pressures of the gases. In this case, the total pressure (Pt) is calculated from the partial pressures of helium (PHe), nitrogen (PN₂) and neon (PNe):
Pt = PHe + PN₂ + PNe
First, we have to convert the partial pressures to the same unit (atm). For this, we have to know that 1 atm=760 mmHg=760 Torr
PHe = 585 mmHg x 1 atm/760 mmHg = 0.77 atm
PN₂= 0.76 atm
PNe= 940 Torr x 1 atm/760 Torr = 1.24 atm
Finally, we calculate the total pressure in atm:
Pt = 0.77 atm + 0.76 atm + 1.24 atm= 2.77 atm
What is the application of flotation
Answer:
The law of floatation is applied in all vessels which travel by waterways that include ships, submarines and ferry boats. It is also applied in some vessels which travel by air ways such as hot air balloon and air ship. Balloons of different colors and shapes are filled with lighter gas so that will float in air.
Answer:
*hot air balloon
*swimming
Explanation:
sna makatulong po:)
Which is the molar mass of BF3?
10.81 g/mol
29.81 g/mol
48.81 g/mol
67.81 g/mol
Answer: The molar mass of [tex]BF_3[/tex] is 67.81 g/mol
Explanation:
Molar mass is defined as the mass in grams of 1 mole of a substance.
S.I Unit of Molar mass is gram per mole and it is represented as g/mol.
Atomic Mass of Boron (B) = 10.81 g
Atomic Mass of Flourine (F) = 18.99 g
Molecular mass of [tex]BF_3[/tex] = 1 (10.81)+3(18.99) g = 67.81 g
Thus molar mass of [tex]BF_3[/tex] is 67.81 g/mol
Can i titrate a solution of unknown concentration with another solution of unknown concentration and still get a meaningful answer
Answer:
No, I don't think so at least
Explanation:
In chemistry, you do calculations to find the concentration of a solution with another solution of KNOWN concentration. Without concentrations of either solution, were would you get values from? Where would you start? :3
You can not titrate a solution of unknown concentration with another solution of unknown concentration and still get a meaningful answer.
Titration involves the standardization of unknown solution using a standard solution. By this definition, titration must involve a standard solution.
Since the two unknown solutions are not standardized, we can never get a meaningful answer because we can not be able to perform any calculation unless we have a standard solution.
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How many moles of water are contained in 0.250 mole
of CuSO4.5H2O?
A) 1.25 B) 4.50 C) 40.0 D) 62.5
Answer:
C. 40
Explanation:
there are 40 moles of water in a 0.250 mole. use the formula to find out
40.0 = 40.0 + 0
Explain how an aqueous acidic solution differs from an aqueous basic solution according to the Arrhenius theory for acids and bases
Answer:
An Arrhenius acid is a substance that associates in water to form hydrogen irons (H+) In other words an acid increases the concentration of H+ ions in an aqueous solution
Plants are living organisms that respond to stimuli, use resources for energy, grow and develop, are organized by cells, and reproduce. A. true B. false
Answer:
true
Explanation:
Answer:
b. trueeeeeeeeeeeeeeeeeeeeeeeeeeee
Directions Identify the reactants and product in the following reaction.
4A1+302 → 2A1203
how do i make chrystals using home suppplies
You could use sodium accetate a put it in water...
Oxycodone (C18H21NO4), a narcotic analgesic, is a weak base with pKb = 5.47. Calculate the pH of a .00250 M oxycodone solution.
Answer: The pH of a 0.00250 M oxycodone solution is 9.96
Explanation:
[tex]C_{18}H_{21}NO_4\rightarrow C_{18}H_{20}NO_3^++OH^-[/tex]
cM 0 M 0 M
[tex]c-c\alpha[/tex] [tex]c\alpha[/tex] [tex]c\times \alpha[/tex]
So dissociation constant will be:
[tex]K_b=\frac{(c\alpha)^{2}}{c-c\alpha}[/tex]
Give c= 0.00250 M and [tex]pK_b[/tex] = 5.47
[tex]pK_b=-log(K_b)[/tex]
[tex]K_b=3.38\times 10^{-6}[/tex]
Putting in the values we get:
[tex]3.38\times 10^{-6}=\frac{(0.00250\times \alpha)^2}{(0.00250-0.00250\times \alpha)}[/tex]
[tex](\alpha)=0.036[/tex]
[tex][OH^-]=c\times \alpha[/tex]
[tex][OH^-]=0.00250\times 0.0369=9\times 10^{-5}[/tex]
Also [tex]pOH=-log[OH^-][/tex]
[tex]pOH=-log[9\times 10^{-5}]=4.04[/tex]
[tex]pH+pOH=14[/tex]
[tex]pH=14-404=9.96[/tex]
Thus pH of a 0.00250 M oxycodone solution is 9.96
How do stomata help a plant maintain balance with their environment?
Stomatal pores in plants regulate the amount of water and solutes within them by opening and closing their guard cells using osmotic pressure. In order for plants to produce energy and maintain cellular function, their cells undergo the highly intricate process of photosynthesis .
For each of the following questions give the name of an element from period 2 lithium to neon which matches the description elements may be used once more than once or not at all
a) an element which has atoms with a full outer shell of electrons
b) an element which exists as both diamond and graphite
c) an element that reacts vigorously with cold water
d) a soft metallic element which is stored in oil
PLEASEEE
The elements of period 2 that satisfy the descriptions are;
a) Neon
b) carbon
c) sodium
c) sodium
What is the periodic table?We know that the periodic table is an arrangement of the elements in the order of their reactivity. We know that the elements that we have are arranged into groups and periods.
The elements that are in the same group do have similar chemical properties while the elements that are in the same period do have the same number of shells. The properties of the elements in a periods tends to change across the period.
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Please help will mark brainliest!! What is the main point of paragraph 3?
Answer:
the highest frequency
Explanation:
Many angiosperms rely on animals for
A fertilization
B pollination
C photosynthesis
D transpiration
