Answer:
If each element can be identified by its spectrum then the composition of an unknown star can be determined
Explanation:
The chemical nature of the elements is that they absorb specific wavelength of light depending on their atom. By spectral analysis of the spectrum of emitted light by a body, the body's composition can therefore be determined. As such in order to determine the composition of distant bodies such as planets, stars and other celestial bodies scientists usually make use of spectroscopy.
Answer:
If each element can be identified by its spectrum then the composition of an unknown star can be determined
Explanation:
What is one way that potential energy might be involved in rescue team missions?
Answer:
You may be saving someone from a rock slide, where the rocks will fall at any time, before they fall they have potential energy.
The one way that potential energy might be involved in rescue team missions to save someone to fall is potential energy is used to hold one.
What is gravity?Gravity is the interaction that is because of the force of energy between the surface of the earth to the mass or any energy present on the earth's surface and the force becomes double with the weight.
The potential energy is a form of energy that is used against gravity to do the work which required energy and in rescue, the energy is needed in every coss to save one.
Therefore, one way that potential energy might be involved in rescue team missions to save someone to fall is because gravitational potential energy is used to hold one.
Learn more about gravity, here:
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what is the valence electron of Molybdenum
Answer:
[tex]\Large \boxed{\mathrm{1 \ valence \ electron}}[/tex]
Explanation:
Molybdenum is an element with an atomic number of 42.
An atom of Molybdenum has 42 electrons.
The electronic configuration of Molybdenum is 2, 8, 18, 13, 1.
The valence electrons are the number of electrons in the last shell.
Molybdenum has 1 valence electron.
hat type of mixture is chicken noodle soup?
1. Science is different than many other ways of thinking because it is based on
-opinions
-facts
-personal viewpoints
-none of the above
Answer:
Facts
Explanation:
You can literally read the lesson it tells you science is
all about facts
Maria wants to enter the science fair at her school. She has a list of ideas for her project. Which questions could be answered through scientific investigation? Check all that apply. Which marine biologist is the smartest? Does the rate of decay have an effect on the amount of gas produced? Is the information about photosynthesis difficult to understand? Which laboratory experiment is the most fun to perform? Which brand of stain remover is the best for getting out laundry stains?
Answer:
Does the rate of decay have an effect on the amount of gas produced?
Which brand of stain remover is the best for getting out laundry stains?
Explanation:
I just did it on Edge
Answer:
Does the rate of decay have an effect on the amount of gas produced?
Which brand of stain remover is the best for getting out laundry stains?
Explanation:
I just did the assignment
Read the two statements given below. Statement 1: All living matter at the smallest level is made of cells Statement 2: New animal cells are formed from pre-existing animals Which of the following best relates the statement to the correct type of theory?
PLS I NEED HELP
Answer:
Statement 1: All living matter at the smallest level is made of cells
Explamation:
All living things are made of cells; the cell itself is the smallest fundamental unit of structure and function in living organisms.
Hope this helps
Answer:
I would say A or C
Explanation: Because Statement 1 sounds like an everyday theory and my other question is Both because they sound the same but... I'm really confused about these Questions Hope I will find my answer
And Please mark me as brainliest
Precision Problems:
A group of students worked in separate teams to measure the length of an object.
Here are their data:
Team 1
2.65 cm
Team 2
2.75 cm
Team 3
2.80 cm
Team 4
2.77 cm
Team 5
2.60 cm
Team 6
2.65 cm
Team 7
2.68 cm
I
cm.
• The average length is
This is the mean or average.
cm.
• Subtract the highest value from the lowest value:
This is the range or spread.
• Divide this number by 2:
cm.
This is the approximate range from the average.
• The precision of the measurement can be shown as average range.
The precision of the measurement was
cm.
Demystifying Scientific Data: RET 2006, Rev 2
25
Answer:
[tex]Precision = 2.70 \± 0.1\ cm[/tex]
Explanation:
Given
The data in the table
Required
Follow the steps appended to the question;
Step 1: Calculate the Mean or Average
Mean = Summation of lengths divided by number of teams;
[tex]Mean = \frac{2.65 + 2.75 + 2.80 + 2.77 + 2.60 + 2.65 + 2.68}{7}\ cm[/tex]
[tex]Mean = \frac{18.9}{7}\ cm[/tex]
[tex]Mean = 2.70\ cm[/tex]
Step 2: Get The Range
[tex]Range = Highest - Lowest[/tex]
[tex]Range = 2.80cm - 2.60cm[/tex]
[tex]Range = 0.2\ cm[/tex]
Step 3: Divide Range by 2
[tex]Approximate\ Range = \frac{1}{2}Range[/tex]
[tex]Approximate\ Range = \frac{1}{2} * 0.2\ cm[/tex]
[tex]Approximate\ Range = 0.1\ cm[/tex]
Step 4: Determine the Precision
[tex]Precision = Average \± Approximate\ Range[/tex]
Substitute 2.70 for Average and 0.1 for Approximate Range
[tex]Precision = 2.70 \± 0.1\ cm[/tex]
Look at the following set of measurements for the length of a test tube made by as student and determine ALL responses that are CORRECT. The actual
value of its length is. 2.04 cm.
A. 2.039 cm
B. 2.040 cm
C. 2.041 cm
D. 3.097 cm
Answer:
2.040 cm
Explanation:
If we study the options closely, we will discover that the chosen option is exactly the same as the actual value of the length of the test tube.
Hence it follows that the option chosen in the answer represents the actual measurement of the length of the test tube as stated above
If an atom has 16 protons, 14 neutrons, and 18 electrons. What is the charge of the nucleus?
. The atom has 2 more electrons than protons giving it a negative charge (2-)
Why is science important?
Answer:
science is valued by the society because the application of scientific knowledge helps to satisfy many basic human needs and improve living standards
Explanation:
Finding a cure for cancer and a clean form of energy are just two typical examples
Answer:
Science is about a whole lot more than that and to sum it up we believe that science is a way of helping the brain grow in finding new knowledge and helps us defeat our curiosity of how the world develops and works today. Science is important because it has helped form the world that we live in today.
Explanation:
In other words, science is one of the most important channels of knowledge. It has a specific role, as well as a variety of functions for the benefit of our society: creating new knowledge, improving education, and increasing the quality of our lives. Science must respond to societal needs and global challenges.
w h y d I d t h I s t a k e m e s o l o n g
you buy 30 g of soda that has a density of 50.0 g/mL. How many L did you buy?
Answer: 0.0006L
Explanation:
The density of a substance is given by the expression;
Density = Mass / Volume
Density = 50g/ml, Mass = 30g, Volume = ?
Making volume the subject of formular, we have; Volume = Mass / Density
∴ Volume = 30 g / 50g/ml = 0.6ml, then to Litre, we divide by 1000
The amount in Litres i bought is 0.0006L
Suppose you have a dozen carbon atoms, a dozen gold atoms, and a dozen iron atoms. Even though you have the same number of each, would you expect them all to have the same mass? Explain.
Answer:
NO!
Explanation:
Not considering isotopes for the moment. All the atoms of any one element have the same mass. From the periodic table, and using whole numbers, you may note that the mass of one atom of hydrogen is one atomic mass unit (amu) and the mass of one carbon atom is 12 amu
So, the one carbon (C) atom is 12 times more massive than one hydrogen (H) atom
If you have the same number or each the carbon atoms will always be 12 times more massive.
The fundamental, concept, is that (again neglecting isotopes) since all the atoms of any one element are the same, we count out atoms by massing the atoms. We choose to measure masses in grams, and the counting units is the mole--a number. Like we count out eggs by the number 12, which we call a dozen, we count out atoms by the number mole which is a huge, huge number 6.02 x 10 to the 23rd power.
To comprehend how large the number mole is, I had various students count out a mole of atoms or a mole of molecules by massing them, and then each brought the mole of what they had into a gym which measured 100ft by 100ft.
The question then became, if you had a mole of raindrops, average diameter 0,04cm, how high would the gym walls have to be to hold the mole of raindrops, assuming no compressing of the water molecules.
The answer is nearly 1,000 times the distance between the earth and the moon. The reaction is WOW, they must be so small, YEP!
They got extra credit if they could come up with another accurate and fun way of describing the number mole.
No! because they have different mass.
Element are made of atoms which are the same. Element do have different mass number. Because there is a dozen atom of carbon and a dozen atom of iron does not make but have the same mass.
The atoms of Iron are different from that of gold and carbon and as such will not have the same mass number.
The mass of iron is 55.845 u.The mass number of carbon is 12.0107 u.The atomic mass of gold is 196.96.Conclusively, The average atomic mass of an element can be gotten fromthe periodic table.
Rowena and helga are both performing an experiment with nickel metal. Rowena has a 5 gram sample and determines the density to be 8.9g/cm3. If helga has a nickel sample that is twice as large and has a mass of 10 grams what would be the density of helgas sample?
Answer:
The density of helgas sample is 17.8 g/cm³.
Explanation:
Given that,
Mass of sample of Rowena = 5 gram
Density = 8.9 g/cm³
Mass of sample of helga = 10 gram
We need to calculate the volume of sample
Using formula of volume
[tex]V=\dfrac{m}{\rho}[/tex]
Where, m = mass
[tex]\rho[/tex] = density
Put the value into the formula
[tex]V=\dfrac{5}{8.9}[/tex]
[tex]V=0.56\ cm^3[/tex]
We need to calculate the density of helgas sample
Using formula of density
[tex]\rho=\dfrac{m}{V}[/tex]
Where, m = mass
V = volume
Put the value into the formula
[tex]\rho=\dfrac{10}{0.56}[/tex]
[tex]\rho=17.8\ g/cm^3[/tex]
Hence, The density of helgas sample is 17.8 g/cm³.
Balance the equation with the correct coefficients.
Explanation:
In general, to balance an equation, here are the things we need to do:
Count the atoms of each element in the reactants and the products.
Use coefficients; place them in front of the compounds as needed.
How long would it take in hours to administer exactly
500 mL of fluid through an IV with a drop factor of
30 gtt/mL. if the drip rate is 60 gttmin?
Answer:
4.167 hours
Explanation:
The drop factor is the amount of fluid falling for one millimeter of fluid in gttt/ml.
The flow rate is the volume administered for a specific period of time in ml/hr = volume / time
The unit of drip rate is gtt/min
The formula that shows the relationship is:
Drip rate = flow rate × drop factor
Given that:
Drip rate = 60 gtt / min, Flow rate = volume / time = 500 ml / t, drop factor = 30 gtt/ml
Drip rate = flow rate × drop factor
60 = 500 / t × 30
500 / t = 60/30
500 / t = 2
2t = 500
t = 500/2
t = 250 mins
1 hr = 60 min
t = 250 / 60 hours = 4.167 hours
A lab technician measures a sample of sulfur dichloride (SCl2) to contain 4.31 x 10^22 molecules of SCl2. How many atoms of chlorine are present in the sample?
Answer:
THE NUMBER OF ATOMS OF CHLORINE IN THE SAMPLE IS 25.95 * 10^45 ATOMS.
Explanation:
Number of molecules = 4.31 * 10^22 molecules of SCl2
From Avogadro's rule which states that equal volume of gases at the same temperature and pressure have the same number of molecules.
1 mole = 6.022 * 10 ^ 23 particles or atoms
So therefore, we equate the given value of SCl2 molecules and solve for the number of atoms of chlorine in the molecule
1 mole = 6.022 * 10^23 atoms
From the break down of SCl2
SCl2 -------> S+ + 2Cl -
So therefore, 2 moles of chlorine is present
2 moles = 2 * 6.022 *10^23
4.31 * 10^22 moles = x atoms
= 4.31 * 10 ^22 * 2 * 6.022 * 10^23 / 2
= 25.95482 * 10^45 atoms
In conclusion, the number of atoms of chlorine present in the sample is 25.95 * 10^45 atoms.
Which statement accurately describes the chemical symbol of an element?
Answer:
hello, i believe there's more information given on the question. could this be a multiple choice question? if yes please comment it below so i can further assist you.
what is (1.2 x 10^6 m) x ( 1.5 x 10^-7m) in scientific notation
Answer:
4.875 × 105
(scientific notation)
= 4.875e5
(scientific e notation)
= 487.5 × 103
(engineering notation)
(thousand; prefix kilo- (k))
Explanation:
This all the ways
which of the following is not a rule when writing a hypothesis.
Will gift brainliest!
Is it testable
Is it a prediction
It must restate the question
It is a if/then statement
Which of these is a dependent variable in this demonstration?
A. the amount of water in the pan
B. the height of the water in the jar
C. the size of the bottle
D. the number of candles in the jar
Answer:
B). The height of the water in the jar.
Explanation:
A dependent variable is characterized as the variable that observes the change or effect caused by experimental manipulation in the independent variable. It is the variable that is being tested in the experiment. In the given experiment of the burning candle, 'the height of water in the jar' will rise or drop with manipulation in the independent variable i.e. 'the number of candles.' Since it is affected by the alteration in other variables, it is the dependent variable. Thus, option B is the correct answer.
Thanks for the help :)
1. Describe what happens when two substances at different temperatures come into contact. Describe how the law of conservation of energy applies to this system.
2. Explain how the calorimeter works, and how you can calculate the heat given off or absorbed by the reaction being studied.
3. A calorimeter contains 500 g of water at 25°C. You place a hand warmer containing 100 g of liquid sodium acetate (NaAC) inside the calorimeter. When the sodium acetate finishes crystallizing, the temperature of the water inside the calorimeter is 32.2°C. The specific heat of water is 4.18 J/g-°C. What is the enthalpy of fusion (ΔHf) of the sodium acetate? Show your work.
Thanks!
1. When two substances at different temperatures come into contact, the substance that is at higher temperature will transfer energy, to the substance at a lower temperature such that their temperature become balanced.
By the law of conservation of energy the heat released by the substance initially at a higher temperature, is the same amount of heat gained by the substance originally at a lower temperature.
2. A calorimeter contains reactants and a substance to determine the heat absorbed, or the heat capacity of materials. This is done using the following equation, Q = mcΔT, where Q = 'heat absorbed / released.'
________________________________
3. We can calculate the energy released by the sodium acetate knowing that all the heat released is absorbed by the water (Part # 1).
[tex]\mathrm{Q =\:m * c * change\:in\:temperature} ,[/tex]
[tex]\mathrm{Q =\:500 * 4.18(specific\:heat\:of\:water) * \mathrm{32.2C -25C} } ,[/tex]
[tex]\mathrm{Q} = 500 * 4.18 * (32.3 - 25) = 15257 \mathrm{J} = 15.257 \mathrm{kJ}[/tex]
Now the enthalpy of fusion is expressed in kJ/mol, so we have to first calculate the moles of sodium acetate.
moles = mass / molar mass
Remember that the molar mass of sodium acetate is 82.0343 g/mol. Therefore the moles will be 100 / 82.0343 = 1.219 mol. Respectively the enthalpy should be 15.257/1.219 = 12.516 kJ/mol.
What's the systematic name of carbon dioxide
it is CO2
Explanation:
A reaction between ammonia gas and chlorine gas produces
ammonium chloride and nitrogen gas. A reaction of 17.0 g of
ammonia with 26.6 g of chlorine gas gives off 3.5 g of nitrogen.
What mass of ammonium chloride is formed in the reaction?
g
Answer:
32.25
Explanation:
8NH3 + 3Cl2 → 6NH4Cl + N2
NH3 = 17 g/mol
number of moles = 1
NH4Cl= 43 g/mol
number of moles = 3/4
mass= 43 × ¾ ≈ 32.25 g
Answer:
40.1
Explanation:
its correct your welcome
At a birthday party in Phoenix, mom and dad begin inflating the balloons with helium. They both notice that the tank begins to cool down as they are inflating the balloon. Why?
Your question has been heard loud and clear.
Well , as the helium flows from tank to balloons , the helium inside the tank decreases , so air fills the remaining space inside the tank. Also , helium is stored under high pressure in the tank because , helium is lighter than air , so its molecules have high energy and this energy causes pressure which increases the temperature. Once the helium is let out , the tank cools down.
Thank you
A chemist adds 190.0mL of a 1.90M nickel(II) chloride NiCl2 solution to a reaction flask. Calculate the millimoles of nickel(II) chloride the chemist has added to the flask. Round your answer to 3 significant digits.
Answer:
361.0 milimoles of nickel chloride
Explanation:
Mili is a unit prefix that represents 1/1000 of the measured value. The multiplication of molarity with volume in liters gives the moles:
190.0mL = 0.190L * (1.90 moles / L) = 0.361 moles -Are moles of NiCl2.
Now, to convert moles to milimoles you must use 1 mole = 1000 milimoles thus:
0.361 moles * (1000 milimoles / 1 mole) =
361.0 milimoles of nickel chloridewhat is 98.723 meters= to blank cm
Answer:
9872.3 cm
Explanation:
A box has a length of 45 centimeters, a width of 7 centimeters, and a height of 15 centimeters. What is the volume? A sample of water has a mass of 14 grams and a volume of 2 cubic centimeters? What is the density of water
Answer:
Hey there!
The volume of the box would be 45(7)(15), or 4725 cm^3.
The density of any object is the mass divided by volume. Thus, the density of the water would be 14/2, or 7 g/cm^3.
Let me know if this helps :)
Assertion (A):. Ionization enthalpy increases for each successive electron in a period Reason (R): Nuclear charge increases across the period (i) Both A and R are true and R is the correct explanation of A. (ii) A is true but R is false. (iii) A is false but R is true. (iv) Both A and R are false.
Answer: Both A and R are false.
Who would have first made this statement while observing cork under a microscope? "The cork looks like little rooms, or cells.”
Answer:
B. Schleiden
Explanation:
i just took the test
Answer:hooke
Explanation:me when your mom
10. Make your own unique problem for your classmates to solve for the
independent, dependent, and controlled variables. Make sure to include the
answers.
Answer:
Explanation:
Problem:
In a gender based experiment, the blood pressure of different ages of men is been checked and recorded to determine if there is any correlation. What will be the independent, dependent and controlled variables?
Answer:
A controlled variable is the variable that is left constant throughout the course of an experiment. The controlled variable here is the gender.
A dependent variable is the variable that is been determined or measured during the course of an experiment. The dependent variable here is the blood pressure.
An independent variable is the variable that is intentionally or decidedly altered during the course of an experiment. The independent variable here is the age.