need help with this science question............

Need Help With This Science Question............

Answers

Answer 1

Answer:

18- H

19- D

20-G

21-A

(i think these are the answers)

Explanation:


Related Questions

A scientist claimed that he radiocarbon dated a fossilized skull of a dinosaur and found it to be about 63 million years old. Do you support his claim? Provide at least one scientifically based reason why you do or do not support the claim.

Answers

Answer:Since dinosaurs are thought to be over 65 million years old, the news is stunning - and more than some could tolerate.  After the AOGS-AGU conference in Singapore, the abstract was removed from the conference website by two chairmen because they could not accept the findings.  Unwilling to challenge the data openly, they erased the report from public view without a word to the authors.  When the authors inquired, they received this letter:

Explanation:

i do not own my copyrights

is 4 Fe + 3 O2 --> 2 Fe2O3
balanced?

Answers

Answer:

Yes the given equation is balanced.

Explanation:

Chemical equation:

Fe + O₂       →     Fe₂O₃

Balanced chemical equation:

4Fe + 3O₂       →     2Fe₂O₃

There are four iron and six oxygen atoms on both side of equation thus the given equation is balanced.

The given reaction also follow the law of conservation of mass.

According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.

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.

This reaction is synthesis reaction:

Synthesis reaction:

It is the reaction in which two or more simple substance react to give one or more complex product.

A + B      →   AB

According to the CDC, influenza is a respiratory illness caused by the flu virus. Some of the symptoms include cough, sore throat, muscle aches, and vomiting.
Which statement represents a reasonable claim about the effects of the flu virus on the body’s ability to maintain homeostasis?
A
Influenza affects one major system, which must work to restore homeostasis.

B
Influenza affects one system, but multiple systems must interact in order to restore homeostasis.

C
Influenza affects multiple systems and multiple systems must interact in order to restore homeostasis.

D
Influenza affects one major system and secondary systems, but the major system works to restore homeostasis.

Answers

Answer:

B. Influenza affects one system, but multiple systems must interact in order to restore homeostasis.

Explanation:

According to the CDC, influenza is a respiratory illness caused by the flu virus of which some symptoms include cough, sore throat, muscle aches, and vomiting.

The statement that represents a reasonable claim about the effects of the flu virus on the body’s ability to maintain homeostasis is that it affects one system which is the RESPIRATORY SYSTEM but multiple systems must intervene in other to maintain homeostatis.

*Homeostatis is the unique way a human body or organism stabilises its internal state despite the changes on the external.

Which particle has the least mass? Proton, a helium atom, electron, hydrogen atom

Answers

Answer:electron

Explanation:

Why is it important to know which category of microorganism has caused an infection?

Select one:
a. Treatment depends on which kind of organism caused the infection.
b. Probiotic infections can actually worsen some conditions.
c. Some infections can indicate cancer.
d. Some types of infections are highly contagious.

PLEASE ANSWER QUICKLY

Answers

ima say a cause it sounds smart realistically

Answer:

A

Explanation:

True or False
ATP energy is used to move muscles and build protein in your body

Answers

True. ATP is released when using your muscles, and it helps break down food giving you protein

need help with this.............................................

Answers

Answer:

fossil layers

Explanation:

what change in the system will increase the boiling point

Answers

Answer:

ExplanationIt is moving from 4s to 8s at a constant speed of 4 cm:

Answer:

Boiling points increase as the number of carbons is increased.

Explanation:

The addition of solutes or other substances usually changes the boiling point. Additionally, changing the pressure on a liquid changes its boiling point. Sugar, salt or other non-volatile solutes in water will usually make the boiling point higher.

The relative strength of the four intermolecular forces is: Ionic > Hydrogen bonding > dipole dipole > Van der Waals dispersion forces. The influence of each of these attractive forces will depend on the functional groups present. Boiling points increase as the number of carbons is increased.

Which of these elements does not bond with other elements to form molecules?

Group of answer choices

Neon

Sulfur

Oxygen

Chlorine

Answers

Answer:

Explanation:b

What is the volume of 100 g neon at STP?

Answers

Answer:

Well

STP

specifies 100⋅kPa,and 273.15⋅K...

Explanation:

And so we solve for n

moles of gas

in the Ideal Gas equation, and of course we have to fish out an appropriate gas constant...

n=PVRT=100⋅kPa×10⋅L8.314⋅L⋅kPa⋅K−1⋅mol−1×273.15⋅K

=0.440⋅mol

And thus a mass of 0.440⋅mol×20.18⋅g⋅mol−1...approx. 9⋅g...

Explanation:

The percent by mass of Ca in CaCl2 is equal to
1. (40/111) x 100
2. (111/40) x 100
3. (3/1) x 100
4. (1/3) x 100

Answers

Answer:

(40/111)×100Here is a bonus Answer✍️✍️Percent composition by elementElement Symbol Mass PercentChlorine Cl 63.888%Calcium Ca 36.112

Mass percentage does not have any unit as numerator and denominator contains the same unit. The percent by mass of Ca in CaCl[tex]_2[/tex] is equal to (40/111) x 100. The correct option is option A.

What is percentage by mass?

Mass percentage represents the the percentage of each element that is making a particular compound.

Mathematically,

Percentage of mass = (component’s mass ÷ total mass) x 100%

Atomic weight of different element of calcium chloride{ CaCl[tex]_2[/tex]} are

Ca = 40 ; Cl = 35

Total mass of Calcium element in calcium chloride = 40g/mol

Total mass of Chlorine atom in calcium chloride = 35× 2= 71g/mol

Total molar mass of calcium phosphate = 40 +71= 111g/mole

Percentage of calcium in calcium chloride =40÷111 = 36%

Therefore, the percent by mass of Ca in CaCl2 is equal to (40/111) x 100. The correct option is option A.

To learn more about mass percentage, here:

https://brainly.com/question/27429978

#SPJ2

Which type of reaction is NaCl + AgNO3 → NaNO3 + AgCl?

synthesis
decomposition
oxidation
replacement

Answers

Answer:

replacement

Explanation:

If the specific heat of water is 4.18 3/g*^ C much heat is required to increase the temperature of 12 g of water from 23 degrees * C to 39 degrees * C ^ 2

Answers

Answer:

Q = 802.6 J

Explanation:

Given data:

Specific heat capacity of water = 4.18 J/g.°C

Mass of water = 12 g

Initial temperature = 23°C

Final temperature = 39°C

Heat required = ?

Solution:

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = 39°C - 23°C

ΔT = 16 °C

Q = 12 g× 4.18 J/g.°C × 16 °C

Q = 802.6 J

Select the correct answer.
Which equation correctly relates kinetic energy, mass, and velocity?
OA. KE=3m22
OB. KE = mv2
Oc. KE=mu
OD. KE = mv3

Answers

Answer:

Ke1/2mv2

Explanation:

Hope this helps

Answer:

KE 1/2 MV2

ExplanationExplanationExplanationExplanation: hope this helps

Can someone plz help-

Answers

Answer:

The answer is 3 :)

Answer: 3. a bottle that was broken into many small pieces

Who asked the question “can you split matter forever?”

Answers

Answer:

Of course, what we today call atoms can be divided into more elementary particles, but not that many.

Explanation:

pls that is the picture ​

Answers

Do what it says easy

During which step of this procedure does a chemical change occur?

A. 1

B. 2

C. 3

D. 4

Answers

I believe the answer is going to be D) 4-Add silver nitrate solution to form a white solid.

A radioactive element having and atomic number 82 and atomic mass 214 emits a beta particle. The resulting element is:______.

Answers

Answer:

[tex]\frac{214}{83} Bi[/tex]

Explanation:

In beta emission, a neutron is converted into a proton thereby reducing the neutron:proton (N/P) ratio.

When a beta emission occurs, the mass number remains the same while the nuclear charge increases by one unit. The daughter nucleus is found one place to the right of its parent in the periodic table.

How many double covalent bonds can form with a hydrogen atom

Answers

answer: covalent bonds

Iron(III) nitrate + potassium sulfide product names

Answers

First write down the chemical formula:

Fe(NO3)3 + K2S

Then, to determine the products use the AD+CB method to form your products:

A = Fe
B = (NO3)3
C = S
D = K2

Products: Fe2S3 + KNO3

Whole equation:

Fe(NO3)3 + K2S -> Fe2S3 + KNO3

Write the balanced chemical equation:

2 Fe(NO3)3 + 3 K2S -> Fe2S3 + 6 KNO3

A motorist discovers that her auto tire measures 29.2 psi rather than the recommended 35 psi. If the tire’s volume is assumed constant at 11.6 L and the temperature is 45F at the filling station, how many moles of air will the motorist need to add to bring the tire to 35 psi? (assume 1.00 atm = 14.7 psi)

Answers

Answer:

  0.20 moles

Explanation:

The pressure is proportional to the quantity of gas at a given temperature and volume. So, the quantity needs to be increased by a factor of ...

  (35 psi)/(29.2 psi) = 175/146 ≈ 1.19863

The fractional increase required is ...

  1.19863 -1 = 0.19863

__

The quantity of air currently in the tire is ...

  1 mol·519.67°R/(atm·23.6442 L) × (29.2/14.7 atm) × (11.6 L) / (45+459.67)°R

  = 1.0035 mol

so we need to add ...

  (fraction to add) × (current quantity) = amount to add

  0.19863 × 1.0035 mol = 0.1993 mol = amount to add

About 0.20 moles of air must be added to the tire to bring the pressure up.

5) How many kilograms are there in 7.50 x 10^26 molecules of sulfuric acid?

Answers

Answer:

I think It might be ( 122.5g )

1. What kinds of metals are REALLY reactive? why?
2. What kinds of non-metals are REALLY reactive? why?
3. What group on the periodic table doesn’t react at all? why?

Answers

Answer:

1. Alkali metals (group 1)

2. halogens (Group 17)

3. noble gasses (group 18)

Explanation:

1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.

2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.

3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)

I hope this helps.  Let me know if anything is unclear.

Why are standard electrode potentials usually measured at 1.0 M electrolyte concentration?

Answers

Answer:

To avoid variation due to concentration

Explanation:

Hope this helps :)

Which statement about the surface of the moon is true?
o There is water and air, but no life on the moon's surface.
O There is no air, wind, liquid water or life on the moon's surface.
There are liquid seas on the moon's surface.
It is very windy on the moon's surface.



Answers

Answer:

There is no air, wind, liquid water or life on the moons surface.

Explanation:

Answer:

ok i know it wont help now bc this was in 2020 but i did this on my lessons and its: There is no air, wind, liquid water, or life on the moon's surface.

Explanation:

i got all the right except the last one

Compare and contrast the mass of the object to the size of the object.

Answers

Mass is the amount of matter an object contains, while volume is how much space it takes up. Take a basketball and a bowling ball, their about the same size but the bowling ball is heavier because it contains more matter.

please help this makes no sense to me!!

Answers

Answer:

potassium nitrate= KNO3 ---> KNO2 + O2 and a gas evolution reaction

Explanation:

i think

The formula for calculating power is work divided by time (power = work + time). What are two ways of stating the same relationship?
work = power + time
nwork s power x time
power
time = work x power
Opower workx time
time
Work

Answers

Answer:

See the answer below

Explanation:

The formula for calculating power is such that;

  power = work/time

Two ways to restate the relationship between the 3 variables would be to make time and work the subject of the formula respectively.

1. When time if made the subject of the formula;

 time = work/time

2. When work is made the subject of the formula;

work = power x time

How many moles of aluminum are equivalent to 4.816 × 1024 atoms?
A.12.5
B.8
C.1.25
D.08

Answers

Answer:

6.591

Explanation:

= 6.951 moles

Answer: 8

Explanation:

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