Date:
Why do scientists study fossils?
A.
to understand how volcanoes are formed
B.
to understand life on Earth as it was millions
of years ago
C.
to understand when mountains were created
Answer:
b
Explanation:
Answer:
I think ur answer would be B
Explanation:
Hope this helps
Two ions have a different number of
Answer:
Explanation:
Isotopes differ in the number of neutrons; in ions the number of electrons is different from the number of protons. Isotopes are atoms that have the same number of protons but different numbers of neutrons.
You have 50 L of CO2 gas at standard temperature and pressure (STP). What would need to be done to the pressure to cut the volume of gas in half?
Answer:
what is this
Explanation:
Answer:
we have to double the pressure.
Explanation:
b/c according to boyle's" the volume of a given mass of gas is inversely proportional to its pressure in a constant temperature.
P1*V1=P2*V2
we have P1=1 atm because it is at STp
V1=50L
V2=25L because we want to cut the volume of the gas in half .
and we can find P2
from the above formula we have P2=P1*V1/V2
P2=1*50/25=50/25=2
so when we doubled the pressure the volume will be halved.
Curicun, named for marie curie, has approximately 25 different isotopes that emit an alpha particle when their nuclei decay. If curium-247, the most abundant nuclide, emit and alpha particle, what daughter nuclide is formed?
Answer: The daughter nuclide formed is Plutonium -243
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
[tex]^A_Z\textrm{X}\rightarrow ^{A-4}_{Z-2}\textrm{Y}+^4_2{\alpha}[/tex]
where A - mass number
Z - atomic number
X and Y are symbols of elements
For alpha decay of curium-247,
[tex]^{247}_{96}\textrm{Cm}\rightarrow ^{243}_{94}\textrm{Pu}+^4_2{\alpha}[/tex]
The daughter nuclide formed is Plutonium -243
Select the answer that lists the radiation waves in order of increasing
energy.
A. Gamma rays, Infrared, Radio waves
B. Radio waves, X-rays, Ultraviolet
C. Visible light, Infrared, X-rays
D. Microwaves, Ultraviolet, X rays
The process of moving water from its source to places where humans use it is called water diversion. true or false
Answer:
That is def true
Explanation:
which two planets have the same density ?
Answer:
Uranus and Neptune
Explanation:
DESPERATE WILL GIVE BRAINLIST
Meiosis produces diploid cells.
True
False
Answer:
FalseMeiosis produces 4 haploid cells. Mitosis produces 2 diploid cells. The old name for meiosis was reduction/ division. Meiosis I reduces the ploidy level from 2n to n (reduction) while Meiosis II divides the remaining set of chromosomes in a mitosis-like process (division).Explanation:
Hope it helps
Answer:
False
Explanation:
Mitosis creates diploid cells, meiosis creates haploid cells.
What must be happening, according to Newton's second law of motion, if a rigid body of unchanging mass is observed accelerating?
A force is being applied to the mass.
A force was once applied but is now not being applied.
The mass must be changing.
No force was or is being applied to the mass.
Answer:
A force is being applied to the mass.
Answer:
A force being applied to the mass is the correct answer
Explanation:
which of the following is a compound A. Iron B. Alloy C. rock salt D. sugar
Answer:
I think iron sorry if its wrong goodluck!
Which statement is true of inclusions?
A. They are older than the rocks that contain them.
B. They are younger than the rocks that contain them.
C. They are the same age as the rocks that contain them.
Sodium chloride can be produced from reacting sodium metal with chlorine gas. Carly reacts 2.6 g of sodium with 5.0 g of chlorine gas. She recovers 5.8 g of sodium chloride from the reaction. What is her percent yield? Carly's percent yield is ___ %
Answer:
87.75%
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2Na + Cl₂ —> 2NaCl
Next, we shall determine the masses of Na and Cl₂ that reacted and the mass of NaCl produced from the balanced equation. This can be obtained as follow:
Molar mass of Na = 23 g/mol
Mass of Na from the balanced equation = 2 × 23 = 46 g
Molar mass of Cl₂ = 2 × 35. 5 = 71 g/mol
Mass of Cl₂ from the balanced equation = 1 × 71 = 71 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mass of NaCl from the balanced equation = 2 × 58.5 = 117 g
Summary:
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂ to produce 117 g of NaCl.
Next, we shall determine the limiting reactant.
This can be obtained as follow:
From the balanced equation above,
46 g of Na reacted with 71 g of Cl₂.
Therefore, 2.6 g of Na will react with = (2.6 × 71)/46 = 4.01 g of Cl₂.
From the calculations made above, we can see that only 4.01 g of Cl₂ at of 5 g given in question reacted completely with 2.6 g of Na. Therefore, Na is the limiting reactant and Cl₂ is the excess reactant.
Next, we shall determine the theoretical yield of NaCl. The limiting reactant will be used to obtain the theoretical yield since all of it is consumed in the reaction.
The limiting reactant is Na and the theoretical yield of NaCl can be obtained as follow:
From the balanced equation above,
46 g of Na reacted to produce 117 g of NaCl.
Therefore, 2.6 g of Na will react to produce = (2.6 × 117)/46 = 6.61 g of NaCl.
Thus the theoretical yield of NaCl is 6.61 g
Finally, we shall determine the percentage yield of NaCl. This can be obtained as follow:
Actual yield of NaCl = 5.8 g
Theoretical yield of NaCl = 6.61 g
Percentage yield =?
Percentage yield = Actual yield /Theoretical yield × 100
Percentage yield = 5.8/6.61 ×100
Percentage yield of NaCl = 87.75%
What involves 2 non metals ionic or covalent bonds
Answer:
A bond forms between two non metals is covalent
Explanation:
For example Chlorine Cl is a non metal bond in Cl - Cl is covalent
Calculate the Ka for a 0.3 M solution of HA (unknown weak acid) if the pH = 3.65. The reaction can be modelled as HA (aq) + H2O (l) ←→ A- (aq) + H3O+ (aq).
The Ka : 1.671 x 10⁻⁷
Further explanationGiven
Reaction
HA (aq) + H2O (l) ←→ A- (aq) + H3O+ (aq).
0.3 M HA
pH = 3.65
Required
Ka
Solution
pH = - log [H3O+]
[tex]\tt [H_3O^+]=10^{-3.65}=2.239\times 10^{-4}[/tex]
ICE method :
HA (aq) ←→ A- (aq) + H3O+ (aq).
0.3 0 0
2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
0.3-2.239.10⁻⁴ 2.239.10⁻⁴ 2.239.10⁻⁴
[tex]\tt Ka=\dfrac{[H_3O^+][A^-]}{[HA]}\\\\Ka=\dfrac{(2.239.10^{-4}){^2}}{0.3-2.239.10^{-4}}\\\\Ka=1.671\times 10^{-7}[/tex]
How would one convert 5 decades to months (1 decade = 10 years)?
Answer:
A decade is 10 years. Therefore you must first multiply ten by five to get 50. After you multiply the 12 months in a year by the 50 years. Your answer should be 600
Explanation:
Answer:its d
Explanation:just took it
10. Which best describes the purpose of food?
A
to kill bacteria
s. to prevent disease
c. to eliminate waste materials
o. to provide fuel for cell processes
Answer:
10. Which best describes the purpose of food? to kill bacteria
. to prevent disease
A student adds a 3.0 g antacid tablet to 35.0 g of water in a bottle. After the reaction is complete, 37.3 g of liquid remains in the bottle.
How much gas was formed in the reaction?
A. 0.7 g
B. 2.3 g
C. 3.0 g
D. 75.3 g
Answer:
A. 0.7 g
Explanation:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
antacid + water → liquid + gas
3.0 g + 35.0 g = 37.3 g + x
38.0 g = 37.3 + x
x = 38.0 g - 37.3 g
x = 0.7 g
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
Which Body system works alone to maintain homeostasis? (pls help)
Answer:
circulatory system
Explanation:
Your circulatory system delivers oxygen-rich blood to your bones. Meanwhile, your bones are busy making new blood cells. Working together, these systems maintain internal stability and balance, otherwise known as homeostasis.
What is the name of this formula MnN?
PLEASE help due in 25 minutes
Determine the mass in grams of each of the following:
5.04 x 1024 atoms N
2.01 x 1024 atoms Ca
8.32 x 1021 atoms Sn
Determine the number of particles contained in each of the following:
50.3 g Cu
145g Si
0.67 g Cl
Answer:
method to do this given in explaination
Explanation:
divide the number of atoms with avagadro constant and multiply with the molar mass of each atom - to obtain the mass in g
divide the mass with molar mass and multiply with avagadro constant to obtain the number of particles
what happends if you pour 1 litre of water on the surface of the moon?will it bounce? serouse answer please !
Answer:
Explanation:
Diffuse water molecules can persist at the Moon's sunlit surface, as discovered by NASA's SOFIA observatory in 2020. Gradually water vapor is decomposed by sunlight, leaving hydrogen and oxygen lost to outer space. Scientists have found water ice in the cold, permanently shadowed craters at the Moon's poles.
In your own words, explain why we have seasons on Earth. Why do some places have all 4 seasons and others seem to only have 1 or 2?
An Amazon box weighs 1000 grams and has a volume of 125 ml, what is its density
Answer:
80
Explanation:
ignore
URGENT!! Can someone help me with this?
A sample of oxygen gas has a volume of 2.1 L at 3.6 atm pressure and 200 K temperature.
What would the volume of this sample be at 1.0 atm and 400 K?
Answer:
15.1L
Explanation:
Given parameters:
Initial volume = 2.1L
Initial pressure = 3.6atm
Initial temperature = 200K
Final pressure = 1 atm
Final temperature = 400K
Unknown:
Final volume of the sample = ?
Solution:
To solve this problem, we are going to use the general gas law or the combined gas law which is expressed below:
[tex]\frac{P_{1} V_{1} }{T_{1} } = \frac{P_{2} V_{2} }{T_{2} }[/tex]
P, V and T are pressure, volume and temperature
1 and 2 are the initial and final states
Now;
[tex]\frac{2.1 x 3.6}{200}[/tex] = [tex]\frac{1 x V_{2} }{400}[/tex]
200V₂ = 3024
V₂ = 15.1L
Answer:
15.1L
Explanation:
Given parameters:
Initial volume = 2.1L
Initial pressure = 3.6atm
Initial temperature = 200K
Final pressure = 1 atm
Final temperature = 400K
Unknown:
Final volume of the sample = ?
Solution:
To solve this problem, we are going to use the general gas law or the combined gas law which is expressed below:
P, V and T are pressure, volume and temperature
1 and 2 are the initial and final states
Now;
=
200V₂ = 3024
V₂ = 15.1L
What percent of total energy consumption in the u.s in 2010 came from hydroelectric power? select the closest answer
Answer:
12% but u can put 8%
Explanation:
when a magnet is moved alongside a wire, what happens?
A. the electric movement stops
B. the protons move to the correct poles
C. the magnet repels like forces
D. the electrons in the wire begin to flow
Explanation:
D.the electrons in the wire begin to flow
how many moles of h20 are produced from 3 moles of oxygen?
Answer:
Stoichiometric Values in a Chemical Reaction
Explanation:
The coefficients next to the reactants and products are the stoichiometric values. They represent the number of moles of each compound that needs to react so that the reaction can go to completion.
Which of the following statements are true about energy and bonds?
Check all that apply.
A. Energy is necessary for bond formation.
B. Breaking bonds does not absorb or release energy.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Answer:
A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released.
Explanation:
Energy is always required for bond formation because when a chemical reaction occurs, either molecular bonds are broken or other bonds are formed to make different molecules. Energy is released during bond formation and is an exothermic process because bond formation represents a stable configuration and the energy lost is released as heat energy that makes it more stable.
Breaking bonds takes energy and is an endothermic reaction because energy is absorbed to break bonds.
Hence, the correct answer is "A. Energy is necessary for bond formation.
C. Breaking bonds takes energy.
D. When bonds are formed, energy is released."
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Is this right? If not which is it pls
Answer:
i believe it is b as well
Explanation:
Balance Na2CrO4 + AlPO4
Answer:
2Na3PO4 + Al2(CrO4)3
Explanation:
these are the products
The balanced equation is 3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃.
Let's consider the unbalanced chemical equation that occurs between Na₂CrO₄ and AlPO₄. This is a double displacement reaction.
Na₂CrO₄ + AlPO₄ ⇒ Na₃PO₄ + Al₂(CrO₄)₃
We will balance it using the trial and error method.
First, we will balance Na atoms by multiplying Na₂CrO₄ by 3 and Na₃PO₄ by 2.
3 Na₂CrO₄ + AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃
Finally, we get the balanced equation by multiplying AlPO₄ by 3.
3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃
The balanced equation is 3 Na₂CrO₄ + 3 AlPO₄ ⇒ 2 Na₃PO₄ + Al₂(CrO₄)₃.
You can learn more about balancing equations here: https://brainly.com/question/7181548