Answer:
7.5 hours
Explanation:
half life is the a period of time the sample takes to be half the amount it started the period with
it means we can express it as
original amount / (2^n) = current amount
where n is the number of periods
in the problem if we put 100 / (2^n) = 6.25
we will find that n = 4
we divide 30 over 4 and we get that half life of each period will be equal to 7.5
The properties of graphene are all of the following except this _______________.
a
high electrical conductivity
b
flexible
c
one layer of atoms thick
d
highly reactive
Answer:
I think it's a flexible
I hope it's helps you
The respiration rate of a goldfish is measured. The goldfish is then placed in cold water and the respiration rate is measured again
Answer:
so the answer are Tyre and he'll to do
A gas has a density of 5.56 g/L. What would the mass in kilograms of 1 m^3 of this gas
Answer:
Mass is 5560 grams
Explanation:
[tex]{ \boxed{mass = density \times volume}}[/tex]
Density is 5.56 g/L
Volume is 1 m³ = 1,000 L
Substitute the following to get mass:
[tex]mass = (5.56 \times 1000) \\ { \boxed{ \boxed{mass = 5560 \: grams}}}[/tex]
Help me with physical science
Answer:ok
Explanation:fish
Convert -8.0 degrees F to
degrees C.
Answer:
Its -22.222C
Explanation:
I hope its helpful.
Answer:
-22.222
Explanation:
:)
Which substance is a mixture?
table salt
gasoline
aluminum
carbon dioxide
Answer:
Answer is Gasoline
Gasoline is a fuel made from crude oil and other petroleum liquids. Gasoline is mainly used as an engine fuel in vehicles. Petroleum refineries and blending facilities produce motor gasoline for sale at retail gasoline fueling stations.
Hope my answer will help you !!
When fossil fuel are burned,carbon dioxide and water are produced.what elements must be contained in fossil fuels
To solve such this we must know the concept of combustion reaction. Therefore, the elements must be contained in fossil fuels are carbon, hydrogen and oxygen.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Combustion reaction is a reaction in which a substance, basically hydrocarbons burns in presence of oxygen to produce carbon dioxide and water. When fossil fuel are burned, carbon dioxide and water are produced. The elements must be contained in fossil fuels are carbon, hydrogen and oxygen.
Therefore, the elements must be contained in fossil fuels are carbon, hydrogen and oxygen.
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Air is made up of different gases, such as oxygen, nitrogen, and carbon dioxide.
Which statement best describes these three components of air?
Oxygen, nitrogen, and carbon dioxide are all classified as pure substances.
Oxygen, nitrogen, and carbon dioxide cannot react with another substance.
Oxygen, nitrogen, and carbon dioxide are chemically bonded to one another.
Oxygen, nitrogen, and carbon dioxide can be classified as elements.
Answer:
they’re all pure substances. Carbon dioxide is not an element
Explanation:
How many elements are in “C2H6O”
Answer:
Ethanol's chemical formula is C2H6O. This chemical formula can also be written as CH3CH2OH or C2H5OH. It is made of nine atoms that include two carbon (C) atoms, six hydrogen (H) atoms, and one oxygen (O) atom.
Explanation:
Answer:
three elements. carbon hydrogen and oxygen
Methane gas that comes out of a bunsen burner contains what type of energy?
A. Light energy
B. Heat/thermal energy
C. Chemical potential energy
D. Electrical energy
What is the term for negative acceleration?
Answer:
negative acceleration describes a decrease in velocity over time. Acceleration is an increase and zero acceleration is no change in velocity.
Explanation:
Need help please
Which of the following physical changes shows a change in a substance’s state of matter?
A. A piece of paper being torn in half
B. Clay being molded into a bowl
C. An ice cube being crushed
D. Liquid water becoming steam
Answer:
c
Explanation:
because when you crush an ice it would break into peace's and the ice would not be a solid
The observed mass of the sun is 6.270 * 10 ^ 26 g but the actual mass of sun is 5.97*10^ 24 kg . The percent error in measurement is 4,78 %
Answer:
False hoge iska answer
Explanation:
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Special structures in the cells of plants capture sunlight energy to power photosynthesis. What materials must plants obtain from their environment to perform photosynthesis?
sunlight, carbon dioxide, and simple sugars
sunlight, water, and carbon dioxide
sunlight, oxygen, and carbon dioxide
sunlight, water, and oxygen
Answer:
Sunlight
Water
And carbon dioxide
Additional information :
6CO2 + 6H2O → C6H12O6 + 6O2
Why is nucleus of an atom charged is negatively charged?
Answer:
Charge is caused by a flow of electrons, since electrons are around the nucleus they can be lost or gained by atoms. When an atom gets charged, it gains a charge, that is, it gains an electron. Since electrons are negatively charged, when an atom gains one, it also becomes negatively charged.
Stars with a greater overall mass are and , and they consume their nuclear fuel .
Answer:
they will expand
Explanation:
as they bring out they become red giants then eventually white dwarfs or the scarier options a black hole
Compound 2 contains 2.0g of hydrogen and 32.0g oxygen. What is the percent compound of each element?
Note down the formula below
[tex]\boxed{\sf Mass\%\;of\; element=\dfrac{Mass\:of\:the\: element}{Mass\;of\:the\: compound}\times 100}[/tex]
Mass of the compound
[tex]\\ \sf\longmapsto 32+2=34g[/tex]
Mass % of Hydrogen:-
[tex]\\ \sf\longmapsto \dfrac{2}{34}\times 100[/tex]
[tex]\\ \sf\longmapsto \dfrac{1}{17}\times 100[/tex]
[tex]\\ \sf\longmapsto 5.8\%[/tex]
Mass % of Oxygen:-
[tex]\\ \sf\longmapsto \dfrac{32}{34}\times 100[/tex]
[tex]\\ \sf\longmapsto \dfrac{16}{17}\times 100[/tex]
[tex]\\ \sf\longmapsto 94.2\%[/tex]
What can a bee sting treated with?
Answer:
Treatment depends on severity
For mild to moderate reactions, treatment involves removing the stinger, washing the area with soap and water, and applying cold compresses or ice. Creams to the affected area can help reduce discomfort. Severe reactions may need adrenaline.
When using an electronic device, such as an electronic balance, the measurement displayed on the screen is assumed to have one estimated digit included. in fact, you'll often sec the estimated digit changing rapidly, because there is fluctuation in the estimate. Explain why it is important to record the zero in the measurement shown to this right,
The zero calibration of the electronic balance allows to maintain the precision of one digit.
Electronic measurement equipment has a mechanism to set the zero of the measurement every time the equipment is turned on, this procedure must be carried out to eliminate:
Possible existence of some material on the plateChanges in the characteristics of the balance completes due to agingCchanges in ambient conditions, for example temperatureChanges in the mass of the plate due to deformation or breakage.
The methods of regurgitating the zero of the balance consists of measuring the weight without masses and bringing this value to zero, in general by changing some adjustable parameter of the balance, for example magnetic field current, reference level with a beam of light.
With this calibration it will be achieved that there is always a precision digit in the readings.
With Electronic Balance Calibration it is possible to have a pressure digit
learn more about electronic balance here:
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Answer:
The zero is the estimated digit.
Explanation:
If the zero was left off of the measurement, people would assume the tenths place was the estimated digit.
i need help guys hurry
Answer:
when an object is at sea level
Explanation:
wherever you are closest to the center of the Earth.
In a synthesis reaction, two atoms of sodium (Na) combine with one molecule of chlorine gas (Cl2) to produce sodium chloride (NaCl). How many molecules of sodium chloride are produced?(1 point)
four
two
one
three
Answer: 2
Explanation: I DID DA TEST
A synthesis reaction is a chemical reaction in which two different atoms interact together to produce a different molecule or compound.
Sodium is an alkali metal with the atomic number 11. It has a +1 valence electron in its outermost shell.
Chlorine is a halogen family element with the atomic element 17. It requires an electron to complete its octet structure.
That is why the bonding reaction between them is called Electrovalent or Ionic bonding.
When 2 moles of Sodium (Na) combines with 1 mole of Chlorine (Cl), we have:
[tex]\mathbf{2 Na_{(s)} + Cl_2_{(g)} \ \to \ 2NaCl_{(s)} }[/tex]
Therefore, from the above reaction, we can conclude that there are two molecules of sodium produced when two atoms of sodium (Na) combine with one molecule of chlorine gas (Cl2).
Learn more about synthesis reaction here:
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Hi, I need help please :)
Which best describes this compound
Answer:
There is nothing to see
Explanation:
You didnt add the image
A 147g piece of metal has a density of 7.00g/mL. A 50mL graduated cylinder contains 20.0mL of water. What is the final volume after the metal is added to the graduated cylinder
Answer: 41.0 ml
Explanation: (147g/7.00g/ml) = 21.0 ml for the metal
Add to 20.0ml to reach 41.0 ml to 3 sig figs
Why is it impossible for an element to have an atomic number of 110.5?
a. atoms of an element have the same whole number of protons and neutrons
b. atoms of an element all have the same whole number of protons
c. exactly half of the isotopes would need an atomic number of 110 and half would need an atomic number of 111 which is very unlikely
d. atoms with atomic numbers greater than 100 are unstable
Answer: B
Explanation: The atomic number is based only on the number of protons in the nucleus of an atom. Since this is a count of whole numbers, it cannot be a decimal. It's either element 110 or 111, not 110.5.
Answer:
B
A
C
A
C
These should be the answers for your test. If you have any questions, please DM me
Que significa HI en educación ambiental
Answer:
Um... Hello in environmental education. i think that what u said :)
Explanation:
Be specific and shorten it in ur own words I’ll brainlist and rate u 5 star! :)
What are the 2 major steps involved in the breakdown of glucose to carbon dioxide; cellular respiration? Explain what happens in each step.
Glycolysis, the splitting of glucose into two 3-carbon molecules.
The citric acid or Krebs cycle, which produces CO2, NADH, FADH2, and ATP.
A car travels 4 miles in 0.08 hours. The speed of the car is miles/hr.
You decide to clean the bathroom. You notice that the shower is covered in a strange green slime. You decide to try to get rid of this slime by adding lemonade juice. You spray half of the shower with lemonade juice and spray the other half of the shower with water. After 3 days of spraying equal amounts 3 times a day, there is no change in the appearance of the green slime on either side of the shower. How many trials are being performed in this example?
Answer:
3
Explanation:
Which of the following is an
example of a homogeneous
mixture?
A. fruit punch
B. a sandwich
C. a toolbox
Answer:
fruit punch
Explanation:
............
