Answer:
4 sig figs.
Explanation:
Significant Figures Rules:
1. Anything that isn't a zero is a sig fig
2. If a decimal point comes after the ones digit, everything before the decimal is counted as sig fig (i.e 2000. would be 4 sig figs).
3. If we are dealing with small decimals, the zero before and after the decimal (i.e 0.002) is a placeholder and is not counted as sig figs.
4. Any zeros between 2 significant digits is considered in sig figs (i.e 2002 would be 4 sig figs).
We look at 0.001022.
We know that 0.00 are not sig figs and are placeholders.
We know that 1022 are significant digits and figures, and we have 4 of them.
Therefore, we have 4 sig figs.
My answer to the question is 4 significant figures.
who is allowed to go into a crime scene after its released?
Answer:
detectives, police officers and occasionaly lawyers/attorneys.
Explanation:
Non essential officers, judges, district attorney investigators, federal agents, victums, witnesses and politics are not permited to enter crime scenes unless they can provide information and history about the event.
PLEASE HELP I HAVE THIS TEST TOMORROW AM GIVING MORE POINTS THAN I SHOULD
When 33 g of CaO and 10 g of H20 react, 2 g of Cao remain unreacted. What is the mass of calcium hydroxide produced?
Answer:
41.11 g of Ca(OH)2.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
CaO + H2O —> Ca(OH)2
Next, we shall determine the masses of CaO and H2O that reacted and the mass of Ca(OH)2 produced from the balanced equation. This can be obtained as follow:
Molar mass of CaO = 40 + 16 = 56 g/mol
Mass of CaO from the balanced equation = 1 × 56 = 56 g
Molar mass of H2O = (2x1) + 16
= 2 + 16
= 18 g/mol
Mass of H2O from the balanced equation = 1 × 18 = 18 g
Molar mass of Ca(OH)2 = 40 + 2(16 + 1)
= 40 + 2(17)
= 40 + 34
= 74 g/mol
Mass of Ca(OH)2 from the balanced equation = 1 × 74 = 74 g
From the balanced equation above,
56 g of CaO reacted with 18 g of H2O to produce 74 g of Ca(OH)2.
Finally, we obtained the mass of calcium hydroxide, Ca(OH)2 produced from the reaction of 33 g of CaO and 10 g of H2O. This can be obtained as follow:
From the question given above, we were told that when 33 g of CaO and 10 g of H2O reacted, 2 g of CaO were remaining. This implies that H2O is the limiting reactant and CaO is the excess reactant.
Thus, we shall use the limiting reactant to determine the mass of calcium hydroxide, Ca(OH)2 produced because it will give the maximum yield as all of it is consumed in the reaction.
The limiting reactant is H2O and the mass of calcium hydroxide, Ca(OH)2 produced can be obtained as follow:
From the balanced equation above,
18 g of H2O reacted to produce 74 g of Ca(OH)2.
Therefore, 10 g of H2O will react to produce = (10 × 74)/18 = 41.11 g of Ca(OH)2.
Therefore, 41.11 g of Ca(OH)2 were obtained from the reaction.
Name a intensive and extensive property of iron
Answer: An extensive property is a property that depends on the amount of matter in a sample. Mass and volume are examples of extensive properties. ... Color, temperature, and solubility are examples of intensive properties.
Explanation:
An intensive property of iron is density while an extensive property of iron is mass.
WHAT ARE INTENSIVE AND EXTENSIVE PROPERTIES?
Intensive properties of a substance/element are those properties that do not depend on the amount of matter. Examples of intensive properties are density, boiling point, melting point etc. Extensive properties are those properties that depend on the amount of matter in a substance. Examples are mass, weight, volume etc.Regarding iron as an element, one intensive property it posseses is density while one extensive property is its mass.
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Identify the pictures that contain molecules.
the one that contains molecule's is the tope one
Really hope this helped :)
Answer:
the answer I sthe first one .
Which of the following is NOT classified as matter?
rock
B.
steam
C.
air
D.
light
How do you find the mass of an element or compound?
Answer:
[tex]147515[/tex]
no inglés sorry
Answer:
by addding up the the mass of protons and neutrons
PLEASE HELP Wendy and Michelle are trying to determine whether their ideas are scientific or pseudoscientific. Wendy's idea is based on experiments, and new observations can improve it. The experimental results of Michelle's idea cannot be verified.
Which statement is correct about Wendy and Michelle's idea?
Both ideas could be scientific.
Neither idea could be scientific.
Only Wendy's idea could be scientific.
Only Michelle's idea could be scientific.
Answer:
C
Explanation:
1. A teacher asks a student to give the number of protons, neutrons,
and electrons in an atom of fluorine.
a. Is this enough information to answer the question?
b. If it is, determine the number of p, nº, and eʻs.
c. If not, what other information is needed?
is adding hydrochloric acid to milk a physical or chemical change?
What's 1.02 x 10^2 in standard notation?
the sample of matter of air
Which of the following phases of matter gives off light?
A. Liquid B. Plasma
C. Gas
D. Solid
Answer:
b.plasma
Explanation:
they jump in a exited energy level and by doing that they give off light
Answer:
b
Explanation:
its plasma
why don't we estimate an additional number on an electrical balance?
List 5 biotic factors inside of a classroom
Which of the following is not an adaptation of California thrashers to life in the chaparral biome? a. a long, curved beak for scratching at the ground b. nesting in late March c. a preference for walking over flying d. nocturnal activity Please select the best answer from the choices provided A B C D
Answer:
D
Explanation:
i think option D
hope this helps
Answer:
D) nocturnal activity
Explanation:
edge 2020
The Gateway Arch in St. Louis, MO is approximately 630 ft tall. How many U.S. half dollars would be in a stack of the same height? Each half dollar is 2.15 mm thick.
Answer:
To equal the height of the Gateway Arch in St. Louis, it would take 76810 half dollars.
Explanation:
If the Gateway Arch in St. Louis is 630 feet high, how many half dollars will it take to equal the height if each half dollar is 2.15mm thick?
First, we convert the ft to cm and the cm to mm.
- 1 ft = 30.48 cm
630 ft = 19202.4 cm
- 19202.4 cm = 192024 mm
Now, if a half dollar is 2.15 mm thick, how many half dollars would it take to equal the height of 192024 mm?
1 half dollar = 2.15 mm
X = 192024 mm
X = 192024 mm / 2.15 mm
X = 76810 half dollars.
A sample of xenon gas collected at a pressure of 948 mm Hg and a temperature of 283 K has a mass of 128 grams. What is the volume of the sample in Liters?
Answer:
V = 1.84 × 10³ L
Explanation:
You need to use the Ideal Gas Law and solve for volume.
PV = nRT
V = nRT/P
First, you need to convert the pressure to atm.
1 atm = 760 mm Hg
948/760 = 1.247 atm
Next, convert grams of xenon to moles. The molar mass is 131.293 g/mol.
128/131.293 = 0.975 mol
You now have all of the values needed.
P = 1.247 atm
n = 0.975 mol
R = 8.314 J/mol*K
T = 283 K
Plug the values in and solve.
V = nRT/P
V = (0.975 × 8.314 × 283)/1.247
V = 1.84 × 10³ L
The volume of the sample will be 1.84 × 10³ L.
why is it important to know what things are made of
Answer:
Explanation:
Knowing what things are made of, especially in the case of a mixture whose constituents still retain there chemical properties, assists in knowing the beneficial and harmful effects of those things.
For a example, a body cream/lotion (a mixture) that contains hydroquinone will give an individual the idea that the body cream is a lightening cream; as hydroquinone is a depigmenting agent that reduces the production of melanin thereby leading to the lightening of the skin.
Another relevant example is the hand sanitizer that is recommended for use of cleaning of hands in order to rid the hands off of corona virus. The recommended hand sanitizer should be made of at least 60% ethanol for effective use (which dissolves the virus). Knowing the components of a sanitizer to be used against the virus will assist an individual at a store make informed decision about purchase.
2.
Reflect polygon P using line l.
P
True or False? Mixtures always result in a chemical reaction because they consist of two or more substances thus combine to create a new product
Answer:
true
Explanation:
Explain why volume is an example of an extensive property and density an intensive property.
Extensive property is dependent on mass. Intensive property is property that depends only on the type of matter rather than the amount. Hense, Volume is an example of Extensive property and Density is an example of Intensive property.
Hope this helps :)
The digit that would have to be estimated in reading this instrument would be the nearest:
A: 0.001 g
B:0.01 g
C: 0.1 g
D: 0.0001 g
Answer:C
Explanation:
.1 is secure
.01 is secure because shows the lines and can line it up.
.001 you can not tell for sure what the last digit it.
The digit that would have to be estimated in the reading given instrument is the nearest 0.1 g. Therefore, option (c) is correct.
What is the uncertainty in the measurements?
Uncertainty means the range of possible values within which the true or actual value of the lies. The term accuracy is commonly used to mean the difference between the actual or true value and a measured result. Since the actual value of a measurement is not known, the accuracy of a measurement is generally not known either.
Uncertainty is almost always to one significant digit. If the uncertainty starts with a one, then sometimes uncertainty to two significant digits. The experimental measurement always rounds to the same decimal place as the uncertainty.
The uncertainties have two components one is bias related to accuracy and the unavoidable random variation that takes place when doing repeated measurements which are related to precision.
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How many sig figs does 0.00002 have?
please help asap !!!!
identify the values that should be tested to see if a change occurs
x - values
y - values
z - values
h - values
Answer:
I think that it is A. x - values
A liquid that occupies a volume of 9.0 L has a mass of 7.2 kg. What is the density of the liquid in kg/L
Answer:
Density = 0.8 kg/LExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]From the question
mass = 7.2 kg
volume = 9.0 L
Substitute the values into the above formula and solve for the density
That's
[tex]Density = \frac{7.2}{9} [/tex]We have the final answer as
Density = 0.8 kg/LHope this helps you
Can somebody please describe in detail the difference between a chemical and physical change/reaction. Please provide examples and do as much as possible if you can. Will reward brainliest.
Answer
A chemical change happens when one chemical substance is transformed into one or more different substances, such as when iron becomes rust. Chemical changes occur through the process of chemical reactions, and the resulting substances have different properties because their atoms and molecules are arranged differently.
Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes are used to separate mixtures into their component compounds, but can not usually be used to separate compounds into chemical elements or simpler compounds
Explanation:
Which feature of a hypothesis leads to a new experiment?
a basis on research
a dependency on prior knowledge
a possible explanation
an ability to be tested
Answer:
d
Explanation:
The feature of a hypothesis leads to a new experiment is an ability to be tested and the correct option is option 4.
A hypothesis is a proposed explanation or prediction for a phenomenon or observation. It is a tentative statement that can be tested through experimentation or further investigation.
A hypothesis is typically based on prior knowledge, research, and observations, and it serves as a starting point for scientific inquiry. It is a crucial step in the scientific method and provides a framework for designing experiments to gather evidence and support or refute the hypothesis.
A well-formed hypothesis should be clear, specific, and testable, allowing for the collection of data and analysis to draw conclusions about the validity of the proposed explanation.
Thus, the ideal selection is option 4.
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What is 7.008 x 10^6 in standard form?
Answer:10
6
=
1000000
or a 1 with 6 zeroes.
Explanation:So
5
⋅
10
6
=
5000000
or five million.
A block of aluminum occupies a volume of 15.0 mL and weighs 40.5 g. What is its density? Answer in g/mL.
Answer:
The answer is
2.7 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]
From the question
mass of aluminum = 40.5 g
volume = 15 mL
Substitute the values into the above formula and solve for the density
We have
[tex]Density = \frac{40.5}{15} [/tex]
We have the final answer as
2.7 g/mLHope this helps you
How can a mixture be separated into pure substances?
Answer:
mixture can be separated into pure substances by simple distillation
A mixture can be separated into pure substances with the utilization of several techniques of physical methods like simple distillation, centrifugation, sedimentation, etc.
What is the function of simple distillation?Simple distillation may be defined as a type of separation technique that involves the separation of solvent from a solution. This technique is utilized for purifying the liquids that comprise either nonvolatile impurities such as sand, salt, and other very small amounts of particles.
Apart from simple distillation, evaporation is also used to eliminate water or any liquid substance from a mixture. It makes the solution or mixture dry with the absolute absence of water.
The Centrifugation technique is used to separate the particles on the basis of their size, shape, density, viscosity, and rotor speed.
Therefore, with the utilization of separation techniques, one can easily separate a mixture into pure substances.
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