Answer:
Speed is 2
Explanation:
Speed = distance ÷ time
90/45=2
Answer: 2
Explanation:
Distance/Time = Speed
A chemistry student mixes 25 milliliters of 3.0 M hydrochloric acid (HCl) with excess sodium hydroxide. The chemicals react according to this chemical equation:
HCl + NaOH → NaCl + H2O.
If the volume of the resulting solution is 68 milliliters, what is the concentration of sodium chloride?
Answer:
1.1 mol/liter
Explanation:
You would use the M1V1 = M2V2 equation to solve this.
We know M1 is 3.0 M, V1 is 25 milliliters, and V2 is 68 milliliters. We need to find M2.
To find M2, first plug in what you know.
(3.0 M)(25 mL) = M2(68 mL)
Then, divide everything by 68 mL to get M2 by itself
Your answer should be a quite large decimal but I rounded it to 1.1 mol/liter.
Answer:
The concentration of sodium chloride is 1.1 moles/liter.
Explanation:
Consider the nuclear equation below. Superscript 222 subscript 86 upper R n right arrow superscript 218 subscript question mark upper P o plus superscript 4 subscript 2 upper H e. Which is the missing value that will balance the equation? 84 86 88 90
Answer:
84
Explanation:
From the question given above, it is evident that 222 86Rn is emitting alpha particle since the daughter nuclei produced has a mass number lesser than 4 when compared to parent element.
Therefore, the miss value in the equation is 84.
Please see attachment for further details
Based on the calculations, the missing value that will balance the equation is: A. 84.
What is an alpha decay?An alpha decay is a type of nuclear reaction in which the atomic nucleus of a radioactive element emits an alpha particle (helium atom), thereby, producing chemical elements with a different atomic nucleus.
In this exercise, we are given the following nuclear equation with an alpha decay:
²²²R₈₆ -----> ²¹⁸Poₓ + ⁴He₂
For the subscript, we have:
86 - 2 = 84.
Read more on alpha decay here: brainly.com/question/23303931
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Several atmospheric gases contribute to global warming: carbon dioxide, methane, and nitrous oxide. Considering this, which choice would do the LEAST to directly reduce atmospheric carbon dioxide.
Answer:
A
help u and it's A
Explanation:
Determine whether these statements describe Geiger counters, scintillation counters, both, or neither. An amplifying device that indicates the presence of ionizing particles A device that permits determination of alpha and beta radiation emitted from a substance Film sensitive to radiation that is removed and developed to measure exposure A device used for monitoring individual cumulative exposure to ionizing radiation
Answer:
An amplifying device that indicates the presence of ionizing particles
GEIGER COUNTERS
A device that permits determination of alpha and beta radiation emitted from a substance
BOTH
Film sensitive to radiation that is removed and developed to measure exposure
NEITHER
A device used for monitoring individual cumulative exposure to ionizing radiation
NEITHER
Explanation:
1. Geiger counters and scintillation counters can be described by statements 1 and 2.
2. Statement 3 refers to film-based radiation detectors, not Geiger counters or scintillation counters.
3. Statement 4 refers to dosimeters, not Geiger counters or scintillation counters.
1. An amplifying device that indicates the presence of ionizing particles: This statement describes both Geiger counters and scintillation counters. Both types of counters use amplifying devices to detect and indicate the presence of ionizing particles.
2. A device that permits determination of alpha and beta radiation emitted from a substance: This statement describes both Geiger counters and scintillation counters. Both types of counters are capable of detecting alpha and beta radiation.
3. Film sensitive to radiation that is removed and developed to measure exposure: This statement describes neither Geiger counters nor scintillation counters. Instead, it refers to film-based radiation detectors, such as photographic film or thermoluminescent dosimeters (TLDs), which are used to measure radiation exposure.
4. A device used for monitoring individual cumulative exposure to ionizing radiation: This statement describes neither Geiger counters nor scintillation counters.
Know more about ionizing particles:
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please help me please
Answer:
b
Explanation:
i read this once and remember,trust me!
Answer:
20 is b and 21 is a.
Please help No Explanation needed. Its science please
Answer:
C, A, A, B, B
Explanation:
Question 5: C. continental drift
Question 6: A. new rock forms
Question 7: A. happens at deep-ocean trenches
Question 8: B. convection currents in the mantle
Question 9: B. convergent boundary
What is the general word equation for salt formation by neutralization?
a. Metal + nonmetal
b. Acid + metal
c. Base + nonmetal
d. Acid + base
Answer:d. Acid+base
Explanation:
Because, The general word equation for salt formation by neutralization is acid + base = salt + water.
Answer:
D ACID + BASE
Explanation:
why do we see only one side of the moon from earth?
Answer:
The moon's period of rotation and revolution are equal
which term names a small icy object that orbits the sun?
Answer:
It a comet
Explanation:
that why they are also called dirty snowballs
Answer:
A comment
Explanation:
Because I took the test and that 100 and because comets are icy and sometimes lead tale of water droplets behind them
A sample of air has a volume of 140.0 mL at 67C. To w
hat temperature must the gas
be lowered to reduce its volume to 50.0 mL at constant pressure?
Answer:
What that means is that when pressure and number of moles are kept constant, increasing the temperature will result in an increase in volume. Likewise, a decrease in temperature will result in a decrease in volume. In your case, the volume of the gas decreased by a factor of about 3, from "140.0 mL" to "50.0 mL".
Please help
What causes a wave to have a higher amplitude?
Answer:
More energy
Explanation:
Wave amplitude is determined by the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude.
Answer:
energy of the disturbance
Explanation:
........ btw bts paved the way I saw you was army and thought I would say that
what causes different colors to appear in the sky?
Answer:
Molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter. Scattering affects the color of light coming from the sky.
Explanation:
How many moles of NaCl are contained in 100.0ml of a 0.20m solution
The map shows the main streams and the the rivers near City A and City B, as well as the nearby factories and farmland, The arrows in
the diagram show the direction of the water flow. City A gets its water from the sunset River and City B gets its water from the Moth Lake. A liquid herbicide was applied to a farmland. What is the greatest risk of using the herbicide?
Select One:
It will pollute the water source for the city A
It will pollute the air for the City B
It will pollute the water source of city B
It will pollute the air for the city A
Answer:
c
Explanation:
the map shows water near the factories go into moth lake so all of the waist will end up there
Could somebody answer these questions for me? Thanks!
1. What percentage of the earth is covered by water?
2. What sorts of signals does the brain use to communicate sensations, thoughts and actions?
3. Did dinosaurs and humans ever exist at the same time?
4. What is Darwin's theory of the origin of species?
5. Why does a year consist of 365 days and a day of 24 hours?
Explanation:
1) %70 earth is water and %30 is land.
2)" The single cells in the brain communicatethrough electrical and chemical signals.
3) b'coz earth revolve around the sun in365 days and rotates on its axis in 24 hours. It takes 365 days , because it takes that much time to complete one revolution and it takes 24 hours,because it takes time to complete one rotation as mercury takes 81 earthdays to complete one revolution.
4) Human originated from Adam And Eve.
Ms. Clark is teaching her class about how plants make food for themselves. On the board, she has written this: __________ + air + water = food for plants
Answer:
sunlight
Explanation:
1. Why is hot air hot?
Answer:
Explanation:
Radiation from the sun heats the ground, then the ground heats the air by process of conduction. When that happens air temp. and density start to change causing air convection currents. Hope I help.
I’ll give Brainliest to the first answer
The amount of elements on the reactants side of an isolated equation are ___________ the amount of __________ that are formed on the ________ side. *
A)close to, ice crystals, cold
B)less than, properties, chemical
C)equal to, elements, products
D)similar, molecules, present
E)more than, elements, products
Answer:
C. equal to, elements, products
Explanation:
I took a quiz and it said this was right
Which has more total Heat Energy/
A.) A cup of HOT coffee
B.) A thermos of HOT coffee
C.) They both have the same amount to heat energy
Answer:
The thermos should have more heat energy because of the greater mass.
what is the compound of libr
Answer:
Lithium Bromide
Explanation:
Answer:
El bromuro de litio es un compuesto químico de litio y bromo. Su carácter higroscópico extremo hace que LiBr sea útil como desecante en ciertos sistemas de aire acondicionado.
Explanation:
Consider the intermediate chemical reactions.
2 equations. First: upper C a (s) plus upper C upper O subscript 2 (g) plus one half upper O subscript 2 (g) right arrow upper C a upper C upper O subscript 3 (s). Delta H 1 equals negative 812.8 kilojoules. Second: 2 upper C a (s) plus upper O subscript 2 (g) right arrow 2 upper C a upper O (s). Delta H 2 equals negative 1, 269 kilojoules.
The final overall chemical equation is Upper Ca upper O (s) plus upper C upper O subscript 2 (g) right arrow upper C a upper C upper O subscript 3 (s).. When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation
When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
Let's consider the following intermediate chemical reactions.
Reaction 1: Ca(s) + CO₂(g) + ½O₂(g) → CaCO₃(s) ΔH₁ = -812.8 kJ
Reaction 2: 2 Ca(s) + O₂(g) → 2 CaO(s) ΔH₂ = -1269 kJ
We want to calculate the enthalpy of the following overall chemical equation.
CaO(s) + CO₂(g) → CaCO₃(s) ΔH = ?
We can apply Hess' law.
What is Hess' law?Hess' law states that regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes.
To apply Hess' law in this case we have to:
Conserve equation 1 as is.Reverse equation 2 and multiply it by 1/2, thus changing the sign of its enthalpy and multiplying it by 1/2.Add both equations and their enthalpies.Ca(s) + CO₂(g) + ½ O₂(g) → CaCO₃(s) ΔH = -812.8 kJ
+
CaO(s) → Ca(s) + ½ O₂(g) ΔH = 634.5 kJ
--------------------------------------------------------------------------------------
CaO(s) + CO₂(g) → CaCO₃(s) ΔH = -178.3 kJ
When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation is halved and has its sign changed.
The complete question is as follows.
Consider the intermediate chemical reactions.
Ca (s) + CO₂ (g) + ½O₂ (g) → CaCO₃ (s) ΔH₁ = -812.8 kJ
2Ca (s) + O₂ (g) → 2CaO (s) ΔH₂ = -1269 kJ
The final overall chemical equation is
CaO (s) + CO₂ (g) → CaCO₃ (s) ΔH = ?
When the enthalpy of this overall chemical equation is calculated, the enthalpy of the second intermediate equation
is halved and has its sign changed. is halved. has its sign changed. is unchanged.Learn more about Hess' law here: https://brainly.com/question/11628413
Answer:
Consider the following intermediate reactions.
CH₄(g)+2O₂(g)⇒CO₂(g)+2H₂O(g) ΔH₁ = -802 kJ
2H₂O(g)⇒2H₂O(I) ΔH₁ = - 88 kJ
The overall chemical reaction is as follows.
CH₄(g)+2O₂(g)⇒CO₂(g)+2H₂O(I) ΔH₂ = -890 kJ
What is the correct enthalpy diagram using the Hess law for this system?
✔️ A←❌ B
❌ C
❌ D
The endocrine system sends hormones through the blood to control the activities of tissues and organs.
Group of answer choices
a. True
b. False
answer:it is false
explanation: as it is true or false I think you don't need explanation
Sulfuric acid (H2SO4) has a molar mass of 98.1 g/mol. How many oxygen atoms are found in 75.0 g of H2SO4? A. 1.15 × 10^23 B. 1.84 × 10^24 C. 4.61 × 10^23 D. 7.87 × 10^23
Answer:
B
Explanation:
first find the no. Of moles of H2SO4
= 75/98.1
= 0.7645
Next step
In on mole of H2SO4 the no.of oxygen atom is 4.
1 H2SO4 : 4 O
0.7645 : x x= 0.7645x4= 3.0581
next multiply avogadros constant
3.0581 x 6.022× 10^23 =1.84x10^24
Mass present in 1 gram of mole substance is called molar mass. Molar mass is calculated by: dividing the mass of the compound in grams by the number of moles present in the substances.
The correct answer is:
option B. 1.84 × 10²⁴
Given,
The mass of sulfuric acid =75.0 gThe molar mass of sulfuric acid = 98.1 g/mol
1.The moles of sulfuric acid can be calculated by
M = m ÷ n
where M is molar mass, m is mass and n moles.
moles of sulfuric acid = mass ÷ molar mass
= 75 g ÷ 98.1 g/mol
=0.7645 moles
Hence moles of sulfuric acid present is 0.7645 moles.
2. 1 mole of sulfuric acid = 4 oxygen atoms.
Then, 0.7645 moles of sulfuric will contain: 0.7645 × 4 = 3.0581 atoms of oxygen
3. Oxygen atoms present in 75.0 g of H₂SO₄ will be calculated by multiplying it with Avogadro's constant:
= 3.0581 x 6.022× 10²³
= 1.84x10²⁴
Therefore, 1.84 × 10²⁴ oxygen atoms will be found in 75.0 g of H₂SO₄.
To learn more about moles follow the given link:
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in a titration 20.0 mL of 0.150 M NaOH(aq) Solution exactly neutralize is 24.0 mL of an HCl solution what is the concentration of the HCl solution
Answer:
0.125
Explanation:
i took a test and got it right choosing this answer hopes this help
Explain why matter takes space
5. What is the % of each element in Al2(Cro4)3?
Explanation:
Utiliza mayúsculas para el primer carácter en el elemento y minúsculas para el segundo carácter. Ejemplos: Fe, Au, Co, Br, C, O, N, F.
Puedes utilizar los paréntesis () o los corchetes [].
During light-dependent reactions, carbon dioxide is converted to glucose.
Group of answer choices
True
False
Answer:The light-independent reactions use the ATP and NADPH from the light-dependent reactions to reduce carbon dioxide and convert the energy to the chemical bond energy in carbohydrates such as glucose.
Explanation:step-by-step
Answer:
FALSE
Explanation:
I just took the test and put true and it was wrong so it's false. Hope this helps and please mark brainliest!
Question 2 options: The Galápagos tortoises are native to seven of the Galápagos Islands, a volcanic archipelago about 620 miles west of the Ecuadorian mainland. With lifespans in the wild of over ____________years, it is one of the longest-lived vertebrates. A captive individual lived at least ______________years!
Answers:
in the wild of over 100 years,...
A captive individual lived at least 255 years!
Explanation:
The giant Galapagos tortoises (Chelonoidis nigra) are famous because this species was observed by Darwin during his travel. This species is native from the Galapagos Islands and currently is in danger of extinction. Galapagos tortoises are recognized as one of the longest vertebrates. In this regard, it is worthy to note that a giant tortoise named Harriet lived 255 years, this specimen was in the Australian Zoo.
does gravity affect the orbit of the international space
Answer:
yes
Explanation:gergrgregbfbwerbebw
Discribe how an internal combustion engine works. What is drawback to the type of power?
Answer:
An internal combustion engine is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. The force of combustion is converted into mechanical energy through the use of levers and gears. The by products of combustion include energy, water vapor, carbon dioxide (CO2), nitric oxide (NO), nitrogen dioxide (NO2), and carbon monoxide (CO). The two primary drawbacks to the internal combustion engine are the primary energy source is non-renewable (fossil fuels) and the by products can have damaging effects on the environment.
Explanation:
