Answer:
LD50 is the amount of a material, given all at once, which causes the death of 50% ... LD100 Lethal dose for 100% of the animal test population ... Researchers can do the test with any animal species but they use rats or mice ... quoted as parts per million (ppm) or milligrams per cubic metre
Explanation: hope this helps :)
A low ph scale would indicate that the water is A. Neutral B. Basic C. Acidic
How many moles of Iron (II) oxide are present in a 34.5 gram sample?
Answer:
0.609 Is the answer.
Explanation:
I hope this helped
HELP ME ASAP!!!!!!!!!!!!!!!!!!!!!!!!!!
Answer:
Digestive
Explanation:
Thermal energy would naturally flow between objects at which temperatures?
O A. from 5°C to -5°C
OB. from 15°C to 15°C
OC. from 35°C to 45°C
OD. from -15°C to 15°C
Answer:
i think the answer is letter C. From 35°c to 45°c
Explanation:
sorry if it is wrong
Which radioisotope requires long-term storage as the method of disposal, to protect living things from radiation exposure over time?
Pu-239
FR-229
Fe-53
P-32
Answer:pu-239
Explanation:
Pu-239 is regarded as the radioisotope requires long-term storage as the method of disposal, to protect living things from radiation exposure over time
Disposal of radioactive nuclear waste is often regarded as a problem.
The waste sources are:
Nuclear power reactors Bomb-related nuclear materialDisposal of bomb-grade plutonium is often difficult.
The longer lived isotopes are:
Plutonium-239 whose t1/2 is 24,110 years, Plutonium-240 whose t1/2 is 6,540 years, Curium-245 whose t1/2 is 8,500 years. etc.The storage of the longer lived elements is through containment for the next several thousand of years.
The control or management of radioactive waste is a hard, multifaceted procedure.
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Would the primary consumers, secondary consumers, or tertiary consumers have more total mass?
Answer:
primary
Explanation:
There are two suspects in a shooting investigation. Bullets are recovered from the crime scene. Both suspects own guns, and these guns have been seized by the police. How will the investigators check to see if one of these guns fired the found bullets?
Answer:
They can check if one of the bullets is gone if the gun was fully loaded or they can see if there is any particles of gun powder on the gun. I may be wrong.
How much force is required to accelerate a 22 kg mass at 6 m/s2?s
Answer:
F=132k.gm/s^2Explanation:
F=m×af=22k.g×6m/s^2f=132k.gm/s^2PLS PLS HELP FAST When a pure substance is heated from 35.0°C to 50.0°C, it absorbs 5,200 J of energy. (50 g) What is the specific heat of the substance? You must show your work for full credit.
Answer:
6.93 J/g C
Explanation:
5200=50 g (15 C)x
5200=750x
Also I just took the test
does carbon dissolve in water
Answer:
yes
Explanation:
CO2 is soluble because water molecules are attracted to these polar areas. The bond between carbon
What geologic process could have formed the channel on Mars?
Answer:
How can we decide which geologic process formed the channel on Mars? Students figure out: The channel on Mars was probably formed by water. The rover Curiosity found rocks near the channel that were made up of many smaller rocks.
Explanation:
Hope it helps! Correct me if I am wrong :>
Can you please mark me as brainlest?
Answer:Water
Explanation:
Water could have formed the channel on Mars because some of the rocks that scientists studied from the earth looks similar to the rocks on Mars.
Can someone help me please
Which mass is made up of 6.02x10^23 atoms? none of these 23 g sodium 42 g krypton 24 g carbon 78 g potassium
Answer:
23 g sodium
Explanation:
In chemistry, one mol (1mol) of a substance equals Avagadro's number or constant (6.02 × 10^23 atoms/particles/molecules).
According to this question in which the mass of different elements were given, the mass of the element that equals 6.02 × 10^23
Using the formula; mole = mass/molar mass
- Sodium = 23g/23g/mol = 1mol
- Krypton = 42g/84g/mol = 0.5mol
- Carbon = 24g/12g/mol = 2mol
- Pottasium = 78g/39g/mol = 2mol
Therefore, from the above illustration, it can be observed that only 23g of sodium contains 1 mol, hence, 23g sodium contains 6.02 × 10^23 atoms.
Match the items to use the analogy of time to the vocabulary of chemistry.
Answer:
1 year- 1 mole
time in general- amount of matter
1 second- 1 atom/ particle
Answer:
1 Year => 1 Mole
Time in General => Amount of Matter
1 Second => 1 Atom/Particle
Explanation:
These pairs make the most sense.
Hope it helps!!!
A closed flask contains gas at STP. If the temperature is raised to 400 K what will the pressure be in atm?
Answer:
The answer is 1.5 atm
Explanation:
How many valence electrons are there in Se atom?
Answer:
4 valence electrons
Despite the fact that the word silicon has a ubiquitous affiliation with all things electronic, Si itself is not a good electrical conductor. It has 4 valence electrons, meaning that filling its outer shell it can form a very strong lattice with 4 neighboring Si atoms-with no un-bonded electrons remaining
Answer:
The numer of valence electrons is defined as the number of electrons present in the outer most shell of the atom.So, in the case if selenium, there are 6.
What is the mass of 3.25 moles of sodium hydroxide (NaOH)?
Answer:
1 mole is equal to 1 moles NaOH, or 39.99711 grams.
Explanation:
Hope this helps have a nice day :)
The statement of the mass of sodium hydroxide (NaOH) is "130 g."
What is mass?A substance is something to do with mass that takes up space. The mass of a compound is the total amount of atoms present in grams that make up a molecule. The grams is the unit of mass.
In order to determine the mass in grams, multiply moles of the substance value by its molar mass to convert moles into grams.
Mole to gram conversion factor,
[tex]=\;given \;mole\;.\;\frac{grams}{1\;mol}[/tex]
Mass of NaOH comes out to be,
[tex]=\;3.25\;mol\;.\;\frac{39.997\;g}{1\;mol}[/tex]
= 129.99 g
= 130 g
Hence the correct answer is 130 g.
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Will there ever be grams of a limiting reactant remaining after a reaction has stopped? Why or why not?
Assuming the reaction is complete, there should be no limiting reactant remaining after a reaction. This is because the limiting reactant, by definition, is "the reactant that is completely used up in a reaction."
SOMEONE SMART HELP PLS!!
How many moles are in 45.5 g of P2O5 ?
Answer:
0.327214 mol
Explanation:
45.5/278.106=0.163607
Then, 0.163607x2= 0.327214
Which statement is true about energy? A. Energy never moves. B. Energy is never destroyed. C. Energy always changes to heat. D. Energy always changes to light.
Answer: energy is never moves
Explanation:
what are particles that differ in number between isotopes
Answer:
Isotopes are atoms of the same element that have different numbers of neutrons but the same number of protons and electrons. The difference in the number of neutrons between the various isotopes of an element means that the various isotopes have different masses.
help plz 8th grade science
Answer:
B
Explanation:
Brainlest is apprciatedddddddddddd
Na2SO4(aq) + CaCl2(aq) --> CaSO4(s) +
2NaCl(aq) is an example of which type of
reaction?
decomposition
synthesis
single replacement
double replacement
Answer:
double replacement
Explanation:
Marcus wants to use two objects to compare the sizes of a proton and an electron. If he uses a basketball for a proton, which object would best represent an electron?
A
a pea
B
a bowling ball
C
a soccer ball
D
a beach ball
Answer:
A
Explanation:
In plant cells, how are chloroplasts and mitochondria related?
Answer:
Mitochondria are the "powerhouses" of the cell, breaking down fuel molecules and capturing energy in cellular respiration. Chloroplasts are found in plants and algae. They're responsible for capturing light energy to make sugars in photosynthesis.
What is the best way to statically charge an object,
Answer:Static electricity can be created by rubbing one object against another object.
Explanation: This is because the rubbing releases negative charges, called electrons, which can build up on one object to produce a static charge
The sample of oxygen which represents the greatest mass is
A.) mole
B.) gram
C.) molecule
D.) liter
Answer:
A
Explanation:
A sorry if not correct
A hydrochloric acid solution contains 36 percent HCl by mass. Calculate its
molality
The surface temperature of a white dwarf is higher than a red supergiant. True or False
Answer:
True.
Explanation: