Answer:
B.
Explanation:
Most species that have lived on Earth are now extinct
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A P E X
The statement that best explains why so many fossils look different from the millions of species currently living on Earth is: B. Most species that have lived on earth are now extinct.
What are fossils ?
The fossil record is evidence that life on Earth has changed over time, with new species evolving and old ones going extinct. It shows the wide range of life that existed throughout Earth's history, including many species that no longer exist today.
The diversity of fossils is primarily due to the extensive range of species that have lived and gone extinct throughout the history of life on Earth.
Although some fossils may have changed over time or contain inaccuracies, they are still crucial for understanding the evolutionary relationships among different species.
Hence, option B is correct.
Find more on fossils:
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Find the mass of 3.27 x 10^23 molecules of H2SO4. Use 3 significant digits
and put the units.
Answer:
Approximately [tex]53.3\; \rm g[/tex].
Explanation:
Lookup Avogadro's Number: [tex]N_{\rm A} = 6.02\times 10^{23}\; \rm mol^{-1}[/tex] (three significant figures.)
Lookup the relative atomic mass of [tex]\rm H[/tex], [tex]\rm S[/tex], and [tex]\rm O[/tex] on a modern periodic table:
[tex]\rm H[/tex]: [tex]1.008[/tex].[tex]\rm S[/tex]: [tex]32.06[/tex].[tex]\rm O[/tex]: [tex]15.999[/tex].(For example, the relative atomic mass of [tex]\rm H[/tex] is [tex]1.008[/tex] means that the mass of one mole of [tex]\rm H\![/tex] atoms would be approximately [tex]1.008\![/tex] grams on average.)
The question counted the number of [tex]\rm H_2SO_4[/tex] molecules without using any unit. Avogadro's Number [tex]N_{\rm A}[/tex] helps convert the unit of that count to moles.
Each mole of [tex]\rm H_2SO_4[/tex] molecules includes exactly [tex](1\; {\rm mol} \times N_\text{A}) \approx 6.02\times 10^{23}[/tex] of these [tex]\rm H_2SO_4 \![/tex] molecules.
[tex]3.27 \times 10^{23}[/tex] [tex]\rm H_2SO_4[/tex] molecules would correspond to [tex]\displaystyle n = \frac{N}{N_{\rm A}} \approx \frac{3.27 \times 10^{23}}{6.02 \times 10^{23}\; \rm mol^{-1}} \approx 0.541389\; \rm mol[/tex] of such molecules.
(Keep more significant figures than required during intermediary steps.)
The formula mass of [tex]\rm H_2SO_4[/tex] gives the mass of each mole of [tex]\rm H_2SO_4\![/tex] molecules. The value of the formula mass could be calculated using the relative atomic mass of each element:
[tex]\begin{aligned}& M({\rm H_2SO_4}) \\ &= (2 \times 1.008 + 32.06 + 4 \times 15.999)\; \rm g \cdot mol^{-1} \\ &= 98.702\; \rm g \cdot mol^{-1}\end{aligned}[/tex].
Calculate the mass of approximately [tex]0.541389\; \rm mol[/tex] of [tex]\rm H_2SO_4[/tex]:
[tex]\begin{aligned}m &= n \cdot M \\ &\approx 0.541389\; \rm mol \times 98.702\; \rm g \cdot mol^{-1}\\ &\approx 53.3\; \rm g\end{aligned}[/tex].
(Rounded to three significant figures.)
Calculate the concentration:
2a) 45g of sodium hydroxide in 3dm3 of solution.
2b) 0.256g of sodium chloride in 500cm3 of solution.
Answer:
2a) 15 g/dm3
2b) 0.512 g/dm3
Explanation:
Use the concentration = mass/volume equation.
2. Combine lead (II) nitrate and potassium iodide solutions.
Pb(NO3)2+ Kl →
2. Combine lead (II) nitrate and potassium iodide solutions.
Pb(NO3)2+ Kl →
3. Combine magnesium metal and hydrochloric acid solution.
Mg + HCl →
4. Electrolysis (splitting) of water.
H2O →
5. Burning magnesium.
Mg + O2 →
Answer:
Pb(NO3)2+ 2Kl →PbI2 + 2KNO3
Mg + 2HCl → MgCl2 + H2
4H2O → 4H^+ + 4OH^-
2Mg + O2 → 2MgO
Explanation:
This question has to do with the balancing of chemical reaction equations. The general rule for balancing chemical reaction equation is that the number of atoms of each element on the left hand side of the reaction equation must be equal to the number of atoms of the same element on the right hand side of the reaction equation.
This principle was followed in balancing each reaction equation above. For instance, in the burning of magnesium, there are two atoms of both magnesium and oxygen on either side of the reaction equation.
What causes heat or the transfer of energy from one object to another
Answer:
The answer is kinetic energy
x=2 and y=3
find the value of
3x + y
3x² - 4
solve this please ty
Answer:
3x+y = 9
3x² - 4 = 8
Explanation:
3x+y
3(2)+3
9
3x2-4
3(2)^2-4
3
The unique shape of DNA allows what
Answer: to copy itself during cell division
Explanation:
True or false: Heterotrophs need to go find and eat food.?
:FALSE
:TRUE
Answer:
Explanation:
Heterotrophs cannot make their own food, so they must eat or absorb it. For this reason, heterotrophs are also known as consumers. Consumers include all animals and fungi and many protists and bacteria. They may consume autotrophs or other heterotrophs or organic molecules from other organisms
P5-F2 + Ar --> ArF3
P5a- How many moles of F2 (Fluorine) are needed to produce 9 mole of ArF3 (Argon trifluoride)?
P5b- How many moles of Argon (Ar) are consumed in a reaction that consumes 5 moles of F2 (fluorine)?
I need the answers for the p5 part please help
Answer:
5a. 13.5 moles of F₂
5b. 3.33 moles of Ar.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
3F₂ + 2Ar —> 2ArF₃
From the balanced equation above,
3 moles of F₂ reacted with 2 moles of Ar to produce 2 moles of ArF₃.
5a. Determination of the number of mole of fluorine, F₂, needed to produce 9 moles of ArF₃.
From the balanced equation above,
3 moles of F₂ reacted to produce 2 moles of ArF₃.
Therefore, Xmol of F₂ will react to produce 9 moles of ArF₃ i.e
Xmol of F₂ = (3 × 9)/2
Xmol of F₂ = 13.5 moles
Thus, 13.5 moles of F₂ is needed.
5b. Determination of the number of mole of Ar needed to react with 5 moles F₂.
From the balanced equation above,
3 moles of F₂ reacted with 2 moles of Ar.
Therefore, 5 moles of F₂ will react with = (5 × 2)/3 = 3.33 moles of Ar.
Thus, 3.33 moles of Ar was consumed.
Yes
OO
No
Balanced or Not Balanced? *
2 NaCl + 2 F2 → 2 NaF + 1 C12
Yes
No
Answer:
No, not well balanced
Explanation:
2Nacl+F2=2Naf+Cl2
Elements are organized on the table according to their _____________ ___________ , usually found near the top of the square.
Answer:
atomic number
Explanation:
Elements are organized on the table according to their atomic number, usually found near the top of the square.
Answer:
by their atomic number
hope this helped
What is matter? Write any two properties of matter?
Answer:
anything that has weight and occupies space
Explanation:
Matter is anything, such as a solid, liquid or gas, that has weight (mass) and occupies space.
For anything to occupy space, it must-have volume.
6. Three ice cubes are placed inside a glass of hot chocolate. Which of the following best
explains the heat transfer occurring inside the glass?
bat abanslate
ITS NUMBER 6!!!
PLZZ HELP ASAP!!!
Which of the following could not be an empirical formula? a CH4 b Na2O c NaCl d H2O2
Answer:
C NaCl will not be an empirical formula.
Answer:
C naCl
Explanation:
it wouldnt be an empiricla formula
how heart attacks and Strokes caused by cholesterol
With high cholesterol, you can develop fatty deposits in your blood vessels. Eventually, these deposits grow, making it difficult for enough blood to flow through your arteries. Sometimes, those deposits can break suddenly and form a clot that causes a heart attack or stroke.
Answer:
Cholesterol is a waxy substance found in your blood. Your body needs cholesterol to build healthy cells, but high levels of cholesterol can increase your risk of heart disease.
With high cholesterol, you can develop fatty deposits in your blood vessels. Eventually, these deposits grow, making it difficult for enough blood to flow through your arteries. Sometimes, those deposits can break suddenly and form a clot that causes a heart attack or stroke.
Explanation:
High cholesterol can cause a dangerous accumulation of cholesterol and other deposits on the walls of your arteries (atherosclerosis). These deposits (plaques) can reduce blood flow through your arteries, which can cause complications, such as:
Chest pain. If the arteries that supply your heart with blood (coronary arteries) are affected, you might have chest pain (angina) and other symptoms of coronary artery disease.
Heart attack. If plaques tear or rupture, a blood clot can form at the plaque-rupture site — blocking the flow of blood or breaking free and plugging an artery downstream. If blood flow to part of your heart stops, you'll have a heart attack.
Stroke. Similar to a heart attack, a stroke occurs when a blood clot blocks blood flow to part of your brain.
In 2005, scientists used cells from a dog named Tai to produce a new puppy with DNA identical to Tai's.
What genetic technology was used?
Answer:
Cloning
Explanation:
This is the process of producing a organism genetically identical to the organism the cells came from.
Answer: cloning
Explanation:
The inflation of airbags is due to the breakdown of a single chemical substance into two separate substances.
Two molecules of sodium azide (NaN3) break down into sodium (Na) and nitrogen gas (N2) during the reaction.
How many sodium (Na) atoms are produced in the reaction?
1 Na atom
2 Na atoms
3 Na atoms
Answer:
The correct answer would be
B. 2 Na atoms
Explanation:
As seen in the picture below,
Which type of bonding forms due to electrical attractions between oppositely charged elements
Answer:
Explanation:
Ionic bond
Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
PLEASE HELP!! Is this an element or compound?
copper (ll). oxide (CuO)
Please hurry!!
Answer: Compound
Explanation:
Copper(II) oxide or cupric oxide is the inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu₂O or copper(I) oxide. As a mineral, it is known as tenorite.
PLEASE HELP: 60 POINTS
Select all that apply!
The emission of a Beta particle has the effect of:
a change in mass of an electron emitted from the nucleus
decreasing mass by one unit
increasing mass by one unit
adding a proton to the nucleus
converting 1 neutron to 1 electron and 1 proton
Which group of microorganisms has the ability to mutate?
The genetic information found in DNA, chromosomes, and determines
A. the traits of the organism
B. the organism as an animal
C. the safety of the nucleus
D. the type of cell
Answer:
a
Explanation:
the traits of the organism
When you watch a sunset, is the Sun really moving across the sky? What's happening?
(Science)
ILL GIVE 100 POINTS!!!HELP!! THIS IS FOR CHEM!!an object acted upon by an unbalanced force will accelerate in the direction of the force is newtons what law?
1:second law
2:first law
3:third law
Al2(SO4)3 + 6 K --- > 3 K2SO4 + 2 Al
In an experiment, 46.8 grams of aluminum sulfate is reacted to make how many grams of potassium sulfate?
A certain first-order reaction has a half-life of 20.0 minutes. How much time is required for this reaction to be 75% complete?
Answer:
X = 2
Explanation:
As you know, the rate of a first-order reaction depends linearly on the concentration of a single reactant. The rate of a first-order reaction that takes the form
Please Help Me. Thank You!!!
Molten aluminium is formed at the ____________ electrode where positive Al3+ ions are reduced to aluminium ions. The liquid aluminium runs to the bottom of the cell, where it is tapped off.
Explanation:
this is you questions answered
The following diagram represents the potential energy for the reaction:
The curves represent two possible reaction paths for the decomposition of ammonia, NH3. One can correctly conclude from the graph that the largest activation energy shown for the decomposition of NH3 corresponds to which labeled interval?
C
E
A
B
D
Answer:
Look in the picture ;)
Explanation:
how many molecules are there in 0.45 moles of so3
Answer:
2.71
Explanation:
What is the molar mass of the following compound: C1H3P2
8. The most common element used in nuclear fission reactors is uranium. The three nuclides, U-233, U-235, and U-238, are isotopes of uranium because they have the same number of protons per atom and...*
(1) the same number of electrons per atom
(2) the same number of neutrons per atom
(3) a different number of electrons per atom
(4) a different number of neutrons per atom
Answer:(D) different number of neutrons per atom
Explanation: Honestly, I just looked it up on Socratic.