Answer:
A
Explanation:
Water freezing and thawing involves no chemical change. It has a chemical formula of H2O whether it is ice or water.
What is not an example of fresh aquatic waters.
Oceans
Lakes
Swamps
Rivers
Answer:
oceans
Explanation:
Tell me if u can and i wamt a Real answer
Answer:
a) Does not describe an element
b) Not possible to tell
c) Describes an element
d) Does not describe an element
e) Describes an element
f) Describes an element
Explanation:
4. What is the difference between an open system and a
closed system?
Systems can exist in three ways as open systems, closed systems, and isolated systems. The main difference between open and closed system is that in an open system, matter can be exchanged with the surrounding whereas, in a closed system, matter cannot be exchanged with the surrounding.
btw why not just look it up on google? btw btw brainliest plz
Baseballs pitched by a machine have a horizontal velocity of 30 meters/second. The machine accelerates the baseball from 0 meters/second to 30 meters/second in 0.5 seconds. If a baseball has a mass of 0.15 kilograms, the force the machine exerts is newtons. Use F = ma, where a = v − u t .
The machine exerts a force of 9 newtons on the baseball to accelerate it from 0 m/s to 30 m/s in 0.5 seconds.
To calculate the force exerted by the machine on the baseball, we can use Newton's second law of motion, which states that force (F) is equal to the product of mass (m) and acceleration (a).
In this case, the acceleration can be determined using the formula a = (v - u) / t, where v is the final velocity, u is the initial velocity, and t is the time taken for the acceleration.
Given:
Mass of the baseball (m) = 0.15 kg
Initial velocity (u) = 0 m/s (as the baseball starts from rest)
Final velocity (v) = 30 m/s
Time (t) = 0.5 s
First, let's calculate the acceleration:
a = (v - u) / t
a = (30 m/s - 0 m/s) / 0.5 s
a = 60 m/s^2
Now, we can use the calculated acceleration and the given mass to determine the force:
F = m * a
F = 0.15 kg * 60 m/s^2
F = 9 N
The machine exerts a force of 9 newtons on the baseball. This force is calculated using Newton's second law of motion, which states that force is equal to mass multiplied by acceleration.
By determining the acceleration of the baseball using the formula a = (v - u) / t and substituting the given values, we find that the acceleration is 60 m/s^2. Multiplying the mass of the baseball (0.15 kg) by the acceleration gives the force exerted by the machine as 9 newtons.
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Scientists share the results of their experiments with other scientists and expect them to try to find flaws in their data and experimental design. What is the purpose of doing this?
A. It provides an easy way to find out which scientists are good at designing experiments.
B. It makes it possible to award grant money for the best research projects.
C. It helps scientists to become better at spotting mistakes
D. It helps scientists to improve their experiments and interpret their data accurately
Answer:
D
Explanation:
knowing all factors is the best approach to understanding a certain subject.
It helps scientists to improve their experiments and interpret their data accurately. The consistency of the data with reality is referred to as data accuracy, which is the represents for data quality.
What is data accuracy ?The consistency of the data with reality is referred to as data correctness, which is the fundamental criterion of data quality.
More precision equates to more conformity, thus correct data must reflect the facts you need.
This implies that the information is accurate and has a dependable, consistent source.
Peer review refers to the process of having the work examined by other scientists who assess the approach and look for any potential errors that could cast doubt on the results.
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What should you do if your hypothesis proves false during an experiment?
A change the data to fit the hypothesis
B form a new hypothesis and plan a new experiment
C repeat the experiment until the results support the hypothesis
D change the procedure to get the
results you want
D because you can easily make mistakes but keep goin to get it right.
2.
Which compound is ionic?
a.
CF4
b.
SO3
C.
H2S
d.
BaCl2
e.
C12H22011
D_____________________₩_
“the density of a subtance generally decreases as the temperature increases”
Answer:
The correct answer is D.
Explanation:
Water can evaporate, and if it does, the density decreases
CuCl2(aq) + NaOH(aq) right-arrow Cu(OH)2(s) + NaCl(aq) what is the ionic equation and net ionic equation ?
Answer:
Reactions are given below.
Explanation:
Chemical equation:
CuCl₂ + NaOH → Cu(OH)₂ + NaCl
Balanced Chemical equation:
CuCl₂(aq) + 2NaOH(aq) → Cu(OH)₂(s) + 2NaCl(aq)
Ionic equation:
Cu²⁺(aq) + 2Cl⁻(aq) + 2Na⁺(aq) + 2OH⁻(aq) → Cu(OH)₂(s) + 2Na⁺(aq) + 2Cl⁻ (aq)
Net ionic equation:
H⁺(aq) + OH⁻(aq) → H₂O(l)
The Cl⁻(aq) and Na⁺ (aq) are spectator ions that's why these are not written in net ionic equation. The Cu(OH)₂ can not be splitted into ions because it is present in solid form.
Spectator ions:
These ions are same in both side of chemical reaction. These ions are cancel out. Their presence can not effect the equilibrium of reaction that's why these ions are omitted in net ionic equation.
5.
The apparatus below was used to make carbon dioxide. Dilute hydrochloric acid was added
to calcium carbonate.
A
0
O
B
о
water
con
calcium carbonate
(a) Identify the pieces of apparatus labelled:
A.....
B. conical Flask
16.45 centimeter = decameter
Answer: 0.01645
Explanation:to long tosovles.
A Brainliest please
Good luck .
What was earth’s surface like? Landmasses? First land plants
Answer:
During the early Paleozoic Era, the Earth's surface was very different from what it is today. The continents were arranged differently, forming one large supercontinent called Pangea. This landmass was surrounded by a single large ocean called Panthalassa. The climate was much warmer and wetter than it is today, with no ice caps at the poles.
The first land plants, known as bryophytes, appeared during the early Silurian Period, around 430 million years ago. These plants were small and simple, lacking roots and vascular tissue. They grew in damp environments, such as along the edges of lakes and streams. They were important in the development of soils and in the colonization of land by other organisms, such as insects and other arthropods.
what is rises when boilings happen?
Answer:
Temperature and Boiling
When boiling occurs, the more energetic molecules change to a gas, spread out, and form bubbles. These rise to the surface and enter the atmosphere. It requires energy to change from a liquid to a gas (see enthalpy of vaporization).
pH is defined as the negative log10 of the hydrogen ion activity, aH+, although general chemistry texts commonly express it in terms of the hydronium ion concentration. Thus, pH = −log10 [H3O+], where [H3O+] represents the concentration of H3O+ in units of moles per liter (M). Calculate the pH or [H3O+], as required, for the following solutions.
{H3O+}= 5.79 X 10^-4M
Answer:
The pH value is 3.23
Explanation:
Given that,
[tex][H_{3}O^{+}]=5.79\times10^{-4}\ M[/tex]
We know that,
pH is defined as the negative log10 of the hydrogen ion activity,
We need to calculate the pH
Using formula of pH
[tex]pH=-log_{10}[H_{3}O^{+}][/tex]
Put the value of [tex][H_{3}O^{+}][/tex]
[tex]pH=-log_{10}(5.79\times10^{-4})[/tex]
[tex]pH=3.23[/tex]
Hence, The pH value is 3.23
1. A student observed a silver, shiny, ductile metal during a lab. Which type of property did
the student observe?
A.Physical property
B.Chemical property
C.Both A and B
D.Neither A or B
Answer:
ok
Explanation:
Answer:
B
Explanation:
Sorry if wrong, brainliest if right please
What is 4.07 cm x 2.3cm, rounded to the correct number of significant figures
Answer:9.361
Explanation:
what is the mass of one mole of bricks
Answer:
2.4 x 1027 g
Explanation:
the mass of 1 mole of brick is 2.4 x 1027 g.
What is the difference between weight and mass?
Weight depends on density and mass depends on gravity.
Mass depends on gravity and weight depends on volume
O Weight depends on gravity and mass is constant.
Both weight and mass are constant
Key differences between Mass and Weight
The weight may vary, but the mass is constant.
The mass is measured in kilograms (kg), while the weight is measured in newtons (N).
Mass refers to the amount of matter an object has, but the weight refers to the force of gravity acting on an object.
Answer:
C. Academic English
Explanation:
just a side note, it'd be alot easier if you put the answers like this:
A. Urban English
B. Standard English, and et
Explanation:
Which reaction will proceed faster? Why?
H
HBr
+ H2O
Br
H
NaBr
+ NaOH
Br
II
Answer:
H2O i think.................................
What is the volume of a cube with dimensions 11.0 cm × 11.0 cm × 11.0 cm in m3?
Answer:
1.33 × 10⁻³ m³
Explanation:
Step 1: Given data
Side of the cube (d): 11.0 cm
Step 2: Calculate the volume of the cube (V)
We will use the following expression.
V = d³
V = (11.0 cm)³
V = 1.33 × 10³ cm³
Step 3: Convert "V" to m³
We will use the conversion factor 1 m³ = 10⁶ cm³.
1.33 × 10³ cm³ × (1 m³ / 10⁶ cm³) = 1.33 × 10⁻³ m³
What masses of sodium chloride, magnesium chloride, sodium sulfate, calcium chloride, potassium chloride, and sodium bicarbonate are needed to produce 1 L of artificial seawater for an aquarium? The required ionic concentrations are [Na+] = 3.28 M; [K+] = 0.0094 M; [Mg2+] = 0.0693 M; [Ca2+] = 0.0115 M; [HCO3−] = 0.0015 M; [Cl−] = 3.32 M; [SO42−] = 0.0652 M.
Answer:
NaCl: 184g
MgCl₂: 6.60g
Na₂SO₄: 9.26g
CaCl₂: 1.28g
KCl: 0.70g
NaHCO₃: 0.13g
Explanation:
To convert these concentrations to masses we need to convert molarity to moles and moles to grams using molar mass of each salt:
[CaCl₂] = [Ca²⁺] = 0.0115M
[HCO₃⁻] = [NaHCO₃] = 0.0015M
[SO₄²⁻] = [Na₂SO₄] = 0.0652M
[Mg²⁺] = [MgCl₂] = 0.0693M
[K⁺] = [KCl] = 0.0094M
And using the concentration of Cl⁻:
[Cl⁻] = [NaCl] + 2[MgCl₂] + 2[CaCl₂] + [KCl]
[3.32] = [NaCl] + 2[0.0693] + 2[0.0115] + [0.0094]
[NaCl] = 3.149M
The masses you need are:
NaCl (Molar mass: 58.44g/mol):
3.149mol/L * 1L * (58.44g/mol) =
184g NaClMgCl₂ (Molar mass: 95.211g/mol):
0.0693mol/L * 1L * (95.211g/mol) =
6.60g MgCl₂Na₂SO₄ (Molar mass: 142.04g/mol):
0.0652mol/L * 1L * (142.04g/mol) =
9.26g Na₂SO₄CaCl₂ (Molar mass: 110.98g/mol):
0.0115mol/L * 1L * (110.98g/mol) =
1.28g CaCl₂KCl (Molar mass: 74.55g/mol):
0.0094mol/L * 1L * (74.55g/mol) =
0.70g KClNaHCO₃ (Molar mass: 84g/mol):
0.0015mol/L * 1L * (84g/mol) =
0.13g NaHCO₃A 48.3 mL sample of gas in a cylinder is warmed from 22 °C to
87 °C. What is its volume at the final temperature?
Answer:
58.94 mL
Explanation:
V1 = 48.3 mL V2 = v mL
T1 = 22 degree celsius OR 295 k T2 = 87 degree celsius OR 360 k
We will use the gas equation:
PV = nRT
Since the Pressure (p) , number of moles (n) and the universal gas constant(R) are all constants in this given scenario,
we can say that
V / T = k , (where k is a constant)
Since this is the first case,
V1 / T1 = k --------------------(1)
For case 2:
Since we have the same constants, the equation will be the same
V / T = k (where k is the same constant from before)
V2 / T2 = k (Since this is the second case) ------------------(2)
From (1) and (2):
V1 / T1 = V2 / T2
Now, replacing the variables with the given values
48.3 / 295 = v / 360
v = 48.3*360 / 295
v = 58.94 mL
Therefore, the final volume of the gas is 58.94 mL
The volume of the sample at the final temperature is 58.94mL
CHARLE'S LAW EQUATION:
The volume of a given gas at a particular temperature can be calculated by using Charles law equation, which is as follows:V1/T1 = V2/T2
Where;
V1 = initial volume of gas (mL)V2 = final volume of gas (mL)T1 = initial temperature of gas (K)T2 = final temperature of gas (K)According to this question,
V1 = 48.3mLT1 = 22°C = 22 + 273 = 295KT2 = 87°C = 87 + 273 = 360KV2 = ?48.3/295 = V2/360
295 × V2 = 48.3 × 360
295V2 = 17388
V2 = 17388 ÷ 295
V2 = 58.94mL
Therefore, the volume of the sample at the final temperature is 58.94mL.Learn more: https://brainly.com/question/3491421?referrer=searchResults
A volume of 40.0 mL of a 0.320 M HNO3 solution is titrated with 0.340 M KOH. Calculate the volume of KOH required to reach the equivalence point
Answer:
Koh of 60 and a half
Explanation:
The curved movement of air or water is the result of which action?
the friction that slows down winds near Earth’s surface
the rotation of Earth on its axis
the different air movements north and south of the equator
winds spinning off the equator
Answer: the rotation of Earth on its axis
Explanation: I just did the quiz in my schoolwork right now and got it right so it is correct!
Have a wonderful day!
Answer:
the rotation of earth on its axis
Explanation:
ya gurl took da test
A certain gas consists of a mixture of two elements. The absorption spectrum of the gas is shown in the image. Which of the following could be the emission spectra of the two elements in the gas? Select all the correct answers.
Answer:
the second and fourth one
Explanation:
i just know lol
The emission spectra of the two elements in the gas is second and third one.
Emission spectra refer to the distinct patterns of light emitted by a substance when it is energized or excited. When atoms or molecules absorb energy, typically in the form of heat or light, their electrons move to higher energy levels. As these excited electrons return to their lower energy levels, they release the excess energy in the form of light. The emitted light consists of a series of discrete wavelengths or colors, which can be separated and observed as a spectrum.
Emission spectra are unique to each element or compound and can be used to identify and characterize them. They provide information about the energy transitions occurring within the atoms or molecules and can be measured using various techniques such as spectroscopy. The emitted wavelengths correspond to specific energy differences between electron energy levels, and the resulting spectrum can appear as a series of distinct lines or bands depending on the nature of the emission process.
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O
Aqueous magnesium nitrate
Mg(NO3)2(aq)
sodium
phosphate
Na3PO4(aq)
Write the balanced molecular equation, including phases, for the reaction of aqueous sodium phosphate with aqueous
magnesium nitrate.
The balanced molecular equation for the reaction of magnesium nitrate, Mg(NO₃)₂ and sodium phosphate, Na₃PO₄ is:
3Mg(NO₃)₂(aq) + 2Na₃PO₄(aq) → 6NaNO₃(aq) + Mg₃(PO₄)₂(s)
How do i write the balanced equation?The balanced molecular equation for the reaction of magnesium nitrate, Mg(NO₃)₂ and sodium phosphate, Na₃PO₄ can be written as illustrated below:
Mg(NO₃)₂(aq) + Na₃PO₄(aq) → NaNO₃(aq) + Mg₃(PO₄)₂(s)
There is 1 atom of Mg on the left side and 3 atoms on the right. It can be balanced by writing 3 before Mg(NO₃)₂ as shown below:
3Mg(NO₃)₂(aq) + Na₃PO₄(aq) → NaNO₃(aq) + Mg₃(PO₄)₂(s)
There is 1 atom of P on the left side and 2 atoms on the right. It can be balanced by writing 2 before Na₃PO₄ as shown below:
3Mg(NO₃)₂(aq) + 2Na₃PO₄(aq) → NaNO₃(aq) + Mg₃(PO₄)₂(s)
There are a total of 6 atom of Na on the left side and 1 atom on the right. It can be balanced by writing 6 before NaNO₃ as shown below:
3Mg(NO₃)₂(aq) + 2Na₃PO₄(aq) → 6NaNO₃(aq) + Mg₃(PO₄)₂(s)
Now, the equation is balanced.
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5000kg of ammonium nitrate per square kilometer of cornfield per year. how much nitric acid would be needed to make the fertilizer needed for 1km2 of cornfield orr year
[tex]NH_3+HNO_3-> NH_4NO_3[/tex]
1 mole of nitric acid produce 1 mole of ammonium nitrate.
moles in 5000 kg of ammonium nitrate :
[tex]n=\dfrac{5000\times 1000}{80}\\\\n=62500\ moles[/tex] ( molecular mass of ammonium nitrate is 80 gm/mol )
So, number of moles of nitric acid required are also 62500 moles.
Mass of 62500 moles of nitric acid :
[tex]mass = 62500\times 63 \\\\mass = 3937500\ gram\\\\mass = 393.75\ kg[/tex]
Hence, this is the required solution.
Analysis of a metal salt CrX3 shows it contains 32.84% cr by mass. What is molar mass of x.
Answer:
35.4451011
Explanation:
Predict the initial and isolated products for the reaction. The starting material is a 6 carbon chain where there is a triple bond between carbons 3 and 4. This reacts with H 2 O, H 2 S O 4, and catalytic H g 2 plus to form an initial product. The initial product converts to the more stable isolated product but is in equilibrium. Hint: the products are isomers and in equilibrium with each other.
Answer:
See explanation and image attached
Explanation:
This reaction is known as mercuric ion catalyzed hydration of alkynes.
The first step in the reaction is attack of the mercuric ion on the carbon-carbon triple bond, a bridged intermediate is formed. This bridged intermediate is attacked by water molecule to give an organomercury enol. This undergoes keto-enol tautomerism, proton transfer to the keto group yields an oxonium ion, loss of the mercuric ion now gives equilibrium keto and enol forms of the compound. The keto form is favoured over the enol form.
Which of the following can be observed only in a microscopic view
A. Foam insulation
B. X ray of a knee joint
C. Shape of a soy bean plant
D. Structure of a muscle cell
Answer:
structure of a muscle cell
