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.
If a lab requires you to use 1.25 mol oxygen gas in a chemical reaction, how many molecules of oxygen will you need?
Answer:
7.53*10²³ molecules of oxygen will you need.
Explanation:
Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) that can be found in the amount of one mole of said substance. Its value is 6.023*10²³ particles per mole. Avogadro's number applies to any substance.
You can then apply the following rule of three: if by definition of Avogadro's Number 1 mole of oxygen gas contains 6.023*10²³ molecules, 1.25 moles contains how many molecules?
[tex]amount of molecules=\frac{1.25 moles*6.023*10^{23}molecules }{1 mole}[/tex]
amount of molecules= 7.53*10²³
7.53*10²³ molecules of oxygen will you need.
10. Air is a homogenous mixture of gases. Oxygen is 20% by volume of air typically. What
amount of moles of oxygen is present in 20 L of air at STP?
Answer:
893 moles
Explanation:
An ideal gas at STP occupies 22.4 liters. Calculating Oxygen as if it were an ideal gas there are . 893 moles of Oxygen in 20.0 liters.
8. Calculate the pH of a solution if the [OH-] concentration is 0.015 M.
A) 1.82
B) 8.82
C) 12.18
D) 4.32
Answer:
1.82
Explanation:
pH is given by the equation
The speed of sound in water is 350m/s. If a sound wave has the frequency of 50Hz.
What would the wavelength of the wave be?
Answer:
Explanation
Let, Wavelength = W,
Given, frequency (f) = 50 Hz, wave velocity (V) = 342 m/s
We know, V = f × W
=> 342 = 50 × W
=> W = 342/50 metre
=> W = 6.84 metre
The pressure in a car tire is 178 kPa at 37°C. After a long drive, the pressure is 275 kPa. What is
the new temp of the air in the tire, assuming the volume is constant?
Answer:
T₂ = 478.93 K
Explanation:
Given that,
Initial pressure, P₁ = 178 kPa
Initial temperature, T₁ = 37°C = 310 K
Final pressure, P₂ = 275 kPa
We need to find the new temp of the air in the tire, assuming the volume is constant. We know that,
[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}\\\\T_2=\dfrac{P_2T_1}{P_1}\\\\T_2=\dfrac{275\times 310}{178}\\\\T_2=478.93 K[/tex]
So, the new temperature is equal to 478.93 K.
which action is an example of an organism maintaining homeostatis
Answer:
[tex]\color{Blue}\huge\boxed{Answer} [/tex]
The body regulates those levels in an example of homeostasis. When levels decrease, the parathyroid releases hormones. If calcium levels become too high, the thyroid helps out by fixing calcium in the bones and lowering blood calcium levels. The nervous system helps keep homeostasis in breathing patterns.
CH3(ch2)2C(ch3)3 IUPAC name please?
Answer:
Explanation:
The name is of the compound is 3,3,4,4-tetramethylhexane.
Someone help me out with this brain pop ⚠️
What do plants do that requires Energy?
Answer:
Photosynthesis
Explanation:
Photosynthesis uses energy from light to convert water and carbon dioxide molecules into glucose (sugar molecule) and oxygen. The oxygen is released, or “exhaled”, from leaves while the energy contained within glucose molecules is used throughout the plant for growth, flower formation, and fruit development.
The results of photosynthesis as glucose and oxygen
A) Photosynthesis
B)Products
C)Chloroplasts
D)Glucose
Answer:
Products
Explanation:
1. Write the chemical symbol for each of the following elements.
Aluminum
Beryllium
Calcium
Flourine
Neon
Nitrogen
Silicon
Silfur
2. Write the name of the element for each of the following symbols.
Ar
B
Li
Na
Fe
3. What is the atomic number for the following elements?
C
Fe
Pb
O
N
Zn
Answer:
Chemical symbol:
Aluminum:Al
Berylium: Be
Calcium: Ca
Flourine: F
Neon: Ne
Nitrogen: N
Silicon: Si
Silfur: S
Element name
Ar: Argon
B: Boron
Li: Lithium
Na: Sodium
Fe: Iron
Atomic number
C:6
Fe: 26
Pb: 82
O: 8
N: 7
Zn: 30
Answer:
aluminum- Al
beryllium- Be
calcium- Ca
flourine- F
neon- Ne
nitrogen- N
silicon- Si
sulfur- S
_____________________________________________________
Ar- argon
B- boron
Li- lithium
Na- sodium
Fe- iron
______________________________________________________
C- 6
Fe- 26
Pb- 82
O- 8
N- 7
Zn- 30
Explanation:
What molecules are affected by injury to the pancreas?
Answer:
Causative/sensitizing factors of pancreatic injury include refluxed bile acids, alcohol, and pH. They largely mediate downstream events such as elevated intracellular Ca2+ via influx through TRPC3 channels and release from IP3 and ryanodine-sensitive Ca2+ stores.
Explanation:
The hammerhead shark can reproduce both sexually and asexually. What characteristic of the offspring would suggest that they were produced
through sexual reproduction? Offspring are-
all the same gender.
genetically diverse.
produced in small number.
produced very slowly.
Answer: I think it is ‘Genetically diverse’
Explanation:
a substance made up of only atoms of one type is called
Answer: chemical element
Explanation: A chemical element is a substance that contains only one type of atom, which is the smallest particle of an element.
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.???
10 How does no-till farming help the environment?
A It decreases soil erosion.
C It increases fertilizer use.
B It increases soil removal.
D It decreases crop yield.
Answer: Answer is A it will decrease soil erosion
Explanation:it just will trust me
Answer:
A.
Explanation:
the soil will not loosen when u till it
Please someone help me and all of the terms do not have to eh used
Answer:
The correct answer is -
1. D. mold
2. A. Cast
3. F. trace fossil
4. C. original material fossils
5. B. fossil record.
Explanation:
Mold is the impression of an organism in a rock that occurs due to the complete dissolving of the organism and only an impression left in sedimentary rocks.
The cast is a fossil copy of an organism in a rock that takes place when water-containing minerals fill the molds and creates a three-dimension copy of the fossil.
Trace fossils are the fossils that are preserved in such a manner that records of biological activity stored only instead of remains of plants or animals.
Storing originals animals or parts of the remaining such as tissue of an organism in natural form is known as original-material fossils.
Fossil records are the fossils ever found or discovered on the earth.
When we look at heat transfer problems that include phase transitions, there can bemanynec-essary steps. Consider a material of massmthat undergoes two phase transitions: from solid toliquid and then from liquid to gas. It starts at an initial temperature ofT0(well below the meltingtemperature ofTm) and it heated until it is a gas at a temperature ofTf(well above the boilingtemperature ofTv). How many different steps (simple temperature changes or phase transitions)of heat transfer would you need for this problem
Answer:
There would be 3 temperature changes and 2 phase transitions
Explanation:
The temperature of the material would first increase from T0 to Tm (its melting point)- This is one temperature change.
It would the change from solid to liquid at its melting point Tm.- This is one phase transition.
Its temperature would then increase from its melting point Tm to its boiling point Tv -This is another temperature change.
It would then change from liquid to gas at its boiling point Tv - This is another phase transition.
Finally, its temperature would then increase from its boiling point to T(f) - This is the third temperature change.
So, there would be 3 temperature changes and 2 phase transitions
what is modal class?
தமிழ் வாழ்க
Answer:
Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency.
Answer:
Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency. For example: if you counted the number of pencils in different pencil cases and you decided to group them.
Explanation:
தமிழன் ❤
Given this balanced equation: CS2 + 3 O2 CO2 + 2 SO2
Calculate how many moles of SO2 can be produced with when given 4 moles of CS2.
58.67 g
Now calculate how many moles of SO2 can be produced with when given 4 moles of O2.
Which one is the limiting reactant (4 moles CS2 or 4 moles of O2)? How do you know?
Answer: The FitnessGram PACER Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The test is used to measure a student's aerobic capacity as part of the FitnessGram assessment. Students run back and forth as many times as they can, each lap signaled by a beep sound.
Explanation:
Deforestation affects which of the following?
O none of the cycles
Owater cycle and carbon cycle
O carbon cycle only
O water cycle only
Answer:
water cycle and carbon cycle
Name the following alkyne:
CH3CH2C = C - CI
Answer:
The answer was be 1-chloro-1-butyne
Explanation:
In other words the answer is option letter A
You welcome have a nice day.
The name of the given alkyne, CH₃CH₂C = C – CI is 1 chloro 1 butyne.
The correct option is A.
What are alkynes?Alkynes are unsaturated hydrocarbons, that have carbon-carbon triple bonds.
Chlorobutyne is colorless and is liquid at room temperature and pressure.
It is polar, but still slightly soluble in water.
Thus, the correct option is A, 1 chloro 1 butyne.
Learn more about 1 chloro 1 butyne.
https://brainly.com/question/26210366
Using this illustration, what is the chemical formula? Picture and possible answers are below.
The answer is It is NH3.....
A student adds 5400.0mL of 0.15M NaOH to 201.2mL of 4.0M NaOH. What is the final [NaOH]?
Answer:
0.287 M
Explanation:
Multiply the concentration of each solution by the volume of each (in liters) to get the moles of NaOH in that solution.
0.15 M • 5.4000 L = 0.81 mol NaOH
4.0 M • 0.2012 L = 0.80 mol NaOH
Add the mol of NaOH together to get the total --> 0.81 + 0.80 = 1.61 mol NaOH
Divide by the total volume of solution (5400.0 mL + 201.2 mL = 5,601.2 mL = 5.6012 L)
1.61 mol / 5.6012 L = 0.287 M NaOH
why does the sky appear orang or red at sunset and sunrise?
Answer:
Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.
if the original volume of a gas was 300 ml at 0.250 atm and 400.0 k what is the volume of the gas at 2.00 atm
Answer:
the answer is 18.75
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
How much water must be added to 40.0 g of CaCl2 to produce a solution that is 35.0 wt% CaCl2?
The mass of water present in the solution is 21.5 g.
What is concentration?Concentration refers to the amount of solute in a solution. There are various ways of expressing concentration such as;
Molar concentrationMass concentrationPercentage concentrationWe have the following information;
Percent concentration = 35.0 %
mass of solute = 40.0 g
Mass of water = ?
So;
35 = x/40 + x × 100/1
35 = 100x/40 + x
35(40 + x) = 100x
1400 + 35x = 100x
1400 = 100x - 35x
1400 = 65x
x = 1400/65
x = 21.5 g
Hence the mass of water is 21.5 g.
Learn more about percent concentration: https://brainly.com/question/1600559
A 4.00g sample of gas is found to exert a pressure of 1.71 atm when confined in 3.60L container at a temperature of 24
Answer:
There are 0.311 moles of gas in the tank
Explanation:
Complete question
A 4.00g sample of gas is found to exert a pressure of 1.71 atm when confined in 3.60L container at a temperature of 241 K. Find the number of moles of the gas
Solution
As we know
[tex]PV = nRT[/tex]
where P is the pressure of the gas in atm
V is the volume in liters
n is the number of moles
R is the gas constant = 0.08206 L·atm/K·mol
and T is the temperature in Kelvin
Substituting the given values in above equation, we get -
[tex]1.71 * 3.60 = n * 0.08206 * 241\\n = 0.311[/tex]
There are 0.311 moles of gas in the tank
An unknown amount of sodium azide (NaN3) reacts and produces 0.033 moles of nitrogen gas. What mass of sodium metal is produced
Answer:
Mass of sodium metal is 130.87 gram
Explanation:
The complete reaction is
2 NaN3 --> 2 Na + 3 N2
We know that PV = nRT
n = [tex]\frac{PV}{RT}[/tex]
On substituting the given values, we get
[tex]n = \frac{\frac{99707}{101325}*75 }{0.082 *(273.15 +15)} \\n = 3.02[/tex]moles of N2
Sodium azide's molar mass
3.02 *(2/3) = 2.013 moles
Mass = 2.03 * 65.01 = 130.87 gram