Answer:
Rubidium Rb was discovered in 1861It was discovered by the German chemist Robert Wilhelm Bunsen and the German physicist Gustav-Robert KirchoffExplanation:
Rubidium was discovered by the German chemists Robert Bunsen and Gustav Kirchhoff in 1861 while analyzing samples of the mineral lepidolite with a device called a spectroscope. The sample produced a set of deep red spectral lines they had never seen before. Bunsen was eventually able to isolate samples of rubidium metal. Today, most rubidium is obtained as a byproduct of refining lithium.
please help me with this chem question!!
Answer:
caca123
Explanation:
UM
Weathering (breaking off sediments upriver), erosion (moving the sediments down river) and finally deposition caused the changes in the river.
What helps hold sediments in place to prevent erosion?
Answer:
Explanation:
Maintaining a healthy, perennial plant cover.
Mulching.
Planting a cover crop – such as winter rye in vegetable gardens. ...
Placing crushed stone, wood chips, and other similar materials in heavily used areas where vegetation is hard to establish and maintain.???
A3.00 mol sample of CO2 (g) is in a rigid 6.00 L container at 400.°C.
Which of the following is the pressure of the gas?
16.4 atm
27.6 atm
200. atm
995 atm
Answer:
i'm thinking 27.6 not sure
Explanation:
The Concrete that surrounds a swimming pool takes less time to heat up than the water in the pool. Why
Answer:
The Concrete has a lower specific heat.
Explanation:
Is there massless ness in space?Why?
Acids are what and can destroy your skin and bones.
Answer:
Yes
Explanation:
Hydrofluoric acid (HF) differs from other acids because the fluoride ion readily penetrates the skin, causing destruction of deep tissue layers, including bone.
1.
What is Mendeleev is known for?
A. creating today's atomic model
B. discovering protons
C. publishing the first periodic table
D. discovering Mendelevium
Answer Choice: C
Explanation: Mendeleev is best known for publishing the first periodic table of elements in 1869, revolutionizing the world's understanding of physics and chemistry; and, really almost every aspect of science.
THIS IS A THREE PART QUESTION IF YOU CAN HELP IT WOULD BE REALLY APPRECIATED SO I DONT FAIL.
1. If I add 2.65L of water to 245 grams of sodium acetate, what is the molarity of the NaC2H3O2 solution?
A. 10.8 m
B. 1.13 m
C. 1.08 m
D. 92.4 m
2. If I add 2.65 L of water to 245 grams of sodium acetate, what is the % by mass of NaC2H3O2 in this solution?
A. 8.46%
B.1.12%
C.10.8%
D.9.25%
3. If I add 2.65 L of water to 245 grams of sodium acetate, what is the mol fraction of NaC2H3O2 in this solution?
A. 0.203
B. 0.0846
C. 0.108
D. 0.0199
Answer:
1. B = 1.13M
2. A. 8.46%
3. D = 0.0199
Explanation:
1. Molarity of a a solution = number of moles of solute/ volume of solution in L
Number of moles of solute = mass of solute/molar mass of solute
Molar mass of NaC₂H₃O₂ = 82 g/mol, mass of NaC₂H₃O₂ = 245 g
Number of moles of NaC₂H₃O₂ = 245 g / 82 g/mol = 2.988 moles
Molarity of solution = 2.988 mols/ 2.65 L = 1.13 M
2. Percentage by mass of a substance = mass of substance /mass of solution × 100%
Mass of 2.65 L of water = density × volume
Density of water = 1 Kg/L = 1000 g/L; volume of waterb= 2.65 L
Mass of water = 1000 g/L × 2.65 L = 2650 g
Mass of solution = mass of water + mass of solute = 245 + 2650 =2895 g
Percentage by mass of NaC₂H₃O₂ = 245/2895 × 100% = 8.46%
3. Mole fraction of NaC₂H₃O₂ = moles of NaC₂H₃O₂/moles of solution
Moles of water = mass /molar mass
Mass of water = 2650 g; molar mass of water = 18 g/mol
Moles of water = 2650 g / 18 g/mol = 147.222 moles
Moles of solution = moles of solute + moles of water = 147.222 + 2.988 = 150.21
Moles of NaC₂H₃O₂ =2.988 moles
Moles fraction of NaC₂H₃O₂ =2.988/150.21 = 0.0199
Barium + Aluminum nitrate —> makes what ?
Answer:
Aluminum sulfate with barium nitrate to produce burin and aluminum nitrate
Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]
Chemical reactions are essential natural processes that take place and are in charge of the innumerable alterations and transformations we experience every day. They include the forming and breaking of chemical bonds between atoms, which causes the atoms to be rearranged to produce new compounds with various properties. The concepts of mass and energy conservation control chemical processes. The idea of balanced chemical equations came about because the total number of atoms of each element involved in a reaction stays constant both before and after the reaction. Aluminium hydroxide and barium nitrate are produced as a result of the chemical reaction between barium and aluminium nitrate. The reaction's balanced equation is as follows: [tex]2 Al + 3 Ba (NO_3)_3 \rightarrow 3 Ba(NO_3)_2 + 2 Al(OH)_3[/tex]
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WILL MARK BRAINLEST
Which of the following are sources of greenhouse gasses? Select all that apply
a
Bike Riding
b
Cow Farts
c
Growing Trees
d
Burning Coal
e
Car Exhaust
Answer:
b and c
Explanation:
sorry if i'm wrong
Answer:
b, c, d, e
Explanation:
A 220.0 mL sample of helium gas is in a cylinder with a movable piston at 105 kPa and 275 K. The piston is
pushed in until the sample has a volume of 95.0 mL. The new temperature of the gas is 310 K. What is the new
pressure of the sample?
274 kPa
216 kPa
Piston
243 kPa
51.1 kPa
Answer:
Explanation:
what did you get?
Two containers, illustrated below, are filled with the same amount and the same kind of ideal gas.
Which statement correctly describes the relationship between the contents of the two containers?
Container 1 particles have higher average kinetic energy and higher temperature than Container 2 particles.
Container 1 particles have lower average kinetic energy and lower temperature than Container 2 particles.
Container 1 particles have lower average kinetic energy and lower temperature than Container 2 particles.
Container 1 particles have lower average kinetic energy and higher temperature than Container 2 particles.
Container 1 particles have lower average kinetic energy and higher temperature than Container 2 particles.
Container 1 and Container 2 particles have the same average kinetic energy and the same temperature.
Container 1 and Container 2 particles have the same average kinetic energy and the same temperature.
Answer:
Container 1 particles have lower average kinetic energy and higher temperature than Container 2 particles.
Explanation:
Kinetic energy is the speed of the particles in the bottle.
As you can see in the illustration below, the patricles in Picture 2 are moving faster than the ones in Picture 1.
The tempature of Container 1 is higher because all of the particles are sitting on top of one another. Not being able to move, their pressure builds up and creates heat.
What fossil helped support Wegener's hypothesis of continental drift?
A. Gondwanaland
B. Kannemeyerid
C. Mesosaurus
D. Glossopteris
Answer:
Glossopteris
Explanation:
Glossopteris is a fossil fern that helped support Wegener's hypothesis.
Hope this helps! Have a great day!
Which of these is a learned behavior of a dog?
1.Begging for food
2.Drinking water
3.Panting on a hot day
4.Chewing on a bone
WILL GIVE BRAINLIEST
Ammonia (NH3) readily dissolves in water to yield a basic solution.
NH3 + H2O → NH4+ + OH-
How is this substance classified?
A.
Arrhenius Base
B.
Arrhenius Acid
C.
Bronsted-Lowry Base
D.
Bronsted-Lowry Acid
Answer:
Qué es Crecimiento poblacional:
El crecimiento poblacional se refiere al incremento del número de habitantes en un espacio y tiempo determinado, el cual se puede medir a través de una fórmula aritmética. También se puede emplear como sinónimo el término crecimiento demográfico.
Cuando se hace mención al crecimiento poblacional se puede hacer referencia a cualquier especie animal, sin embargo, se suele usar para referirse a los seres humanos, en especial cuando se realizan investigaciones acerca del crecimiento de la población.
Los datos que se obtienen de estos análisis son de gran importancia, tanto para los gobiernos de un país como, para las diferentes organizaciones internacionales.
Cabe resaltar que durante el siglo XX la población de seres humanos ha crecido y sigue creciendo en gran porcentaje, lo que ha generado preocupación, en especial por sus consecuencias sobre el uso y cuidado de los recursos naturales, entre otros.
Las zonas urbanas son las que presentan mayor crecimiento demográfico, así como, los países en vías de desarrollo. Por el contrario, el crecimiento poblacional es menor en los países desarrollados.
Por ejemplo, el crecimiento poblacional en México ha ido en aumento a lo largo de su historia, es el país con más habitantes hispanohablantes en América Latina. México tiene una población aproximada a 130 millones de habitantes, y se estima que seguirá creciendo gracias a diversos factores gracias a su continuo desarrollo político, económico y social.
At a football stadium, 5% of the fans in attendance were teenagers. If there were 160 teenagers at the football stadium, what was the total number of people at the stadium?
Answer:
yes
Explanation:
bc god exist
Answer:
3200
Explanation:
what type of wave moves the particles parallel to the motion of the wave
a.electromagnetic
b. longitudinal
c. transverse
d.water
Answer:
c
Explanation:
what is the formula for chlorine monobromide
Based on how to wrire chemical formulae, the formula for chlorine monobromide is BrCl.
What is chlorine mononbromide?Chlorine monobromide is a covalent compound formed from the covalent combination of chlorine and bromine.
The covalent bond is formed from the sharing of electrons between atoms chlorine and bromine.
Br2 + Cl2 ---> 2 BrCl
Tye formula of chlorinr monobromide is BrCl.
It is also known as bromine monochloride.
Therefore, the formula for chlorine monobromide is BrCl.
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Balance the following equation: Fe2O3 + H2O --> Fe(OH)3
A.3,2,1
B.2,2,3
C.1,3,2
D.5,2,10
Answer:
answer is c
Explanation:
hope it helps!!!
Cyanobacteria, also known as blue-green algae, are a kind of bacteria found in lakes. These organisms make their own food through photosynthesis. Small animals including mayfly larvae eat the cyanobacteria, and small fish such as yellow perch eat the larvae. The small fish provide food for larger fish, such as walleye.
Choose the level of the food pyramid that represents the energy role of cyanobacteria in the lake ecosystem.
How much more heat does it take to vaporize 1 mole of ethanol than to melt it?
Answer:
I do not know how to solve this bit i THINK 38.56
Explanation:
A gas is most likely to change the liquid phase in the pressure of the gas
Answer: if pressure rises in closed vessel and temperature is low enough,
Gas may condense to liquid state
Typically, this happens when we raise the pressure at room temperature, but there are other situations that aren't covered, including lowering the temperature at room pressure.
What is temperature?Temperature is defined as a measurement of an object or substance's warmth or coldness in relation to a standard value. As opposed to extensive characteristics, like mass or volume, temperature is referred to as an intense property—one that is independent of the quantity of matter being considered—along with pressure, density, and other comparable properties.
If the temperature is low enough and pressure rises in a closed vessel, A gas can turn into a liquid form.
Thus, typically, this happens when we raise the pressure at room temperature, but there are other situations that aren't covered, including lowering the temperature at room pressure.
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For a reaction to be in equilibrium.... *
A. concentration of reactants and products remain constant
B. concentration of reactants and products must be the same
C. the rate of forward reaction is not equal to the rate of backward reaction.
Answer: C) the rate of forward reaction is not equal to the rate of backward reaction. This should be the answer.
Explanation:
Waves that we cannot actually see (unlike ripples in water) and that DO NOT need a medium to travel through belong to which category of waves?
Answer:
electromagnetic waves
Explanation:
The waves that do not need a medium to travel through are known as electromagnetic waves.
What are electromagnetic waves?These waves do not need any medium for their propagation or traveling. The waves have different wavelength and energy factors depending upon their rate of propagation. EMR waves travel from the sun to the earth in space.
Examples of electromagnetic waves are Xrays, gamma rays, radio waves, and more.
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How do properties of water break down rocks?
Answer:
Explanation:
Freezing water can break rock without any change in the minerals that form the rock (physical weathering). This usually produces small particles and sand. Water with dissolved gases and other chemicals causes the minerals in rocks to be changed, leading to the deterioration of the rock (chemical weathering).
chemical weathering
Explanation:
freezing water when mix with it cause detorilation of rocks
What is the charge of a Li ion?
A. +1
B. +2
C. -1
D.-2
Answer:
A
Explanation:
because the charge of Li ion is +1 well I don't know the explanation yet but I'm sure about the answer
Select the correct answer.
Which statement best describes how chemical equations demonstrate conservation of mass?
A.
The number of reactants is the same as the number of products.
B.
The compounds are the same on each side of the reaction.
C.
The number of atoms of each element is the same on each side of the equation.
D.
The state of matter is the same on each side of the equation.
"C" is correct.
The Law of Conservation of Mass states that matter can be neither created nor destroyed. This is evident in chemical equations as you will always start and end with the same amount of atoms of every element. They are all still there; they have just been rearranged.
Answer: C) The number of atoms of each element is the same on each side of the equation.
Explanation: Mass cannot be created nor destroyed.
What is the density of krypton gas (MM = 83.8 g/mol) at 3.00
atm and 100. °C?
g/L
Answer:
8.21
Explanation:
Is the following chemical equation balanced? 1 C2H6+ 102 - 3 H2O + 2
CO2 *
Answer:
No
Explanation:
Answer: smallest whole numbers are 2, 7, 4 and 6
Explanation: C2H6 + 3.5 O2. ⇒ 2. CO2 + 3 H2O
Which of the following has the greatest influence on the size and force of waves?
A.
seasons
B.
Moon’s gravity
C.
wind speed
D.
Earth’s gravity