Answer:
Explanation:
250 cm^3 of 0.2 moldm-3 H2SO4 can be prepared from 150cm^3 of 1.0 moldm^-3 by dilution.
150cm^3 of the 1.0 moldm^-3 stock solution is measured out using a measuring cylinder and transferred into a 250 cm^3 standard volumetric flask and made up to mark. The resulting solution is now 250cm^3 of 0.2 moldm-3 H2SO4.
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
The helium-filled blimp shown in fig. p1.34 is used at various athletic events. determine the number of pounds of helium within it if its volume is 68,000 ft3 and the temperature and pressure are 80 f and 14.2 psia, respectively.
Answer:
The number of pounds of helium n = 666.995 lbm
Explanation:
Given that :
the volume V = 68000 ft³
the temperature T = 80 f = (80 + 460)°R =540°R
the pressure P = 14.2 psia
Using the ideal gas equation PV =nRT to determine the number of pounds of helium within, we have :
n = PV/RT
where;
R = 2.6809 psia. ft³/lbm.R (from the tables of A-1E for helium)
n = (14.2 × 68000)/(2.6809 × 540)
n = 965600/1447.686
n = 666.995 lbm
∴
The number of pounds of helium n = 666.995 lbm
After which problem solving stage should you take action?
One must have to identify the issues first. Then he must measure the problem and then check out the available solutions. He must analyze the options and identify the correct one. After all these steps he can take the action.
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.
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
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.
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.
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 energy transfer is occurring when a battery-powered toy rolls across the floor? a Stored mechanical energy is converted to thermal energy. b Stored mechanical energy is converted to mechanical energy. c Stored chemical energy is converted to thermal energy. d Stored chemical energy is converted to mechanical energy.
Answer:
The correct option is;
d Stored chemical energy is converted to mechanical energy
Explanation:
Energy is stored in a battery in the form of electric potential energy. The chemical in a battery are such that they have an electric potential between them when charged and when the terminals of the battery are connected to an external circuit, the potential difference between the compounds at the poles causes electric current to flow from one pole, across the circuit and enter back into the battery through the other pole
The energy of the moving electrons can then be used to do mechanical work such as causing the mechanism of a coil in a magnetic field to rotate. The rotation can then be used to turn the wheels of the toy using gears.
what is 98.723 meters= to blank cm
Answer:
9872.3 cm
Explanation:
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
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.
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
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.
A student wants to conduct an experiment to find out how pulse rate changes as the length of time spent exercising increases the dependent variable will be
Answer:
I'm not 100% percent sure what your question is, but here is what I think you are asking.
Explanation:
The dependent variable is pulse rate and the indepedent variable is the amount of exericse. The dependent variable changes as the independnet variable changes.
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.
What's the systematic name of carbon dioxide
it is CO2
Explanation:
Question 1
1. Mass reflects the amount of matter in an object.
True
False
Question 2
2. On Earth, your weight is exactly the same where ever you go.
True
False
Question 3
3. On Earth, your mass is exactly the same where ever you go.
True
False
Answer:
1. True.
2. False.
3. True.
Explanation:
1. Mass is simply defined as the quantity of matter present in a body. This means that mass gives us an idea of the amount of matter present in any object or body.
Therefore, the answer to the question is True.
2. Weight of an object is simply defined as the gravitational pull of the earth on an object. This implies that location of the object will greatly influence it's weight as the gravitational pull will varies from place to place. Hence, the weight of the object will differ as the location of the object changes.
Therefore, the answer to the question is False.
3. As defined above mass is the amount of matter present in an object.
The mass of an abject is constant irrespective of the location of the object.
Therefore, the answer to the question is True.
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
Write a full equation for the reactions between magnesium and sulfuric acid
Explanation:
Hey there!!
See solutions in picture.
Hope it helps..
Define Chemistry in your own words .
Answer: The study of elements and their compounds and reactions with one another.
Explanation: ACTUAL DEFINITION (Chemistry is the scientific discipline involved with elements and compounds composed of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances.)
Organic Chemistry: the chemistry of carbon compounds
Inorganic Chemistry: deals with chemicals
Chemistry:-The branch of science deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they change, interact, combine, and the use of these processes to form new substances.
To know more about:-
brainly.com/question/9457867
Quantization of energy lab Hypothesis: Make a prediction that describes the relationship between the composition of an unknown substance and its emission spectrum. For example, “If each element can be identified by its ______________, then the ____________ of an unknown star can be determined." variables: independent - dependent- control-
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:
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.
All the elements in group 18 are in a gaseous state (state true or false)
Answer:
The correct option is;
True
Explanation:
The noble gases are the group 18 elements, all of which are monoatomic gases, located in the extreme right of the periodic table. Due to their filled outermost or valence shells,and their nonreactive nature, the noble gases where initially known as inert gases.
The noble gases have very low melting points and boiling points as hey have very weak inter atomic forces between their atoms such that they all appear as gases under standard atmospheric temperature and pressure conditions.
Today you will be using the bunsen burner in your experiment. Which of the following is a precaution that should be taken before beginning?
Answer:
See the answer below
Explanation:
Although there are no specific options available to choose from, some of the general safety measures or precautions that must be observed when using a bunsen burner are as follows:
Always leave, at least, 12 inches of space between the bunsen burner and the nearest object. This is to avoid the nearby object catching fire accidentally.Always watch the flame at all times, never leave it unattended to.Burners should not be handled unless ample time has been given for them to cool down. This is to avoid burning-related injuries.Burner fittings should be carefully checked to ensure there are no leakages. Gas leakages may cause serious accidents.Always use a sparker as this is safer than using matches or lighter.The gas supply must always be turned off whenever the burner is not in use.For this experiment, students should wear a lab coat and safety eyewear. Students should not touch the flame. They need to keep loose clothing, jewelry, hair, and any flammable substances away from the flame.
Now select a longer period, say the fourth period, starting with the element in the 1A group. Again, go from left to right. What do you notice about the pattern of change in the electron configuration as you go from left to right?
Answer:
The pattern of change in the electron configuration increases from left to right across the period.
Explanation:
In the periodic table, elements having the same number of electrons in the outermost shell of their atoms are placed over one another in vertical columns. Each of the vertical columns is known as a group or family. while each of the resulting horizontal rows is known as a period or row.
There are 18 vertical columns and seven periods in the periodic table. Each period begins with an atom having a valence electron and ends with an atom having a complete outer shell structure of an inert gas.
The fourth period of the periodic table (d-block) consists of the transition elements.
The electron distribution into the energy levels of sublevels of atoms can be shown in any of the tree important electronic configuration.
Electronic configuration shows the sequence of filling electrons into the orbitals of the sublevels as guided by some principles.
The maximum number of electrons in the orbitals of sublevels are two for s-sublevel(one orbital) ; six for p-sublevel( three orbital); ten for d-sublevel ( five orbitals) and fourteen for f-sublevel( seven orbitals). This indicates that the maximum number of electrons in an orbital is two
In the Periodic table ,The sublevels with lower energies are filled up before those with higher energies. One important thing about this principle is that the sublevels do not fill up in numerical order. The pattern of filling is as follows:
1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f etc.
Answer:
In the electron configuration of potassium, I observe that after the 3p orbital is filled, the next electron enters the 4s orbital instead of the 3d orbital because 3d is at a higher energy than 4s. This pattern shows that orbitals fill up according to the Aufbau principle. As I move on right, the number of electrons increases by one for each element until vanadium is reached. The electron configuration of chromium shows all Half-filled orbitals in the 4s and 3d energy levels. Again, as I move right, an exception occurs at copper. Copper’s electron configuration shows completely filled 4s and 3d orbitals. This is an exception to the Aufbau principle to attain more stable electron configurations, whenever possible. Half-filled electron configurations are more stable than other configurations and completely filled electron configurations are the most stable.
Express
[tex] {5}^{n + 2} - {5}^{n + 1} - {5}^{n} [/tex]
in the simplest form
Answer:
[tex]5^{n}[/tex]x19
Explanation:
[tex]5^{n+2}[/tex]-[tex]5^{n+1}[/tex]-[tex]5^n[/tex]
[tex]5^n[/tex](5²-[tex]5^{1}[/tex]-[tex]5^{0}[/tex])
[tex]5^n[/tex](25-5-1)
5^n(19)
[tex]5^{n}[/tex]x19
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 :)
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
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]