Which element is the
most reactive?
A . Silicon
B. oxygen
C. lithium
D . Aluminum

Answers

Answer 1
c. which is oxygen !! :)

Related Questions

If the atom has a MASS of 127 and 45 NEUTRONS, then it contains how many
PROTONS

Answers

Answer:

53

Explanation:

because minus 3

How does your Skeletal and Muscular Systems work together?
Muscles move your bones
Bones move your muscles
Heart pumps blood throughout the body
Your bones protect your muscles

Answers

Answer:

Answer would be A, Muscles move your bones

Explanation:

Without the Muscular System, your bones would not be connected properly

^^yea what they said

What property of water makes it possible for water from the ground to travel all the way up to leaves in the tops of tall trees?​

Answers

Answer:

cohesion-tension

Explanation:

i did the quiz.

Which of the following solutions is basic?a. [H3O+] = 1.0 x 10-10 Mb. [OH-] = 1.0 x 10-10 Mc. [H3O+] > 1.0 x 10-7 Md. [OH-] < 1.0 x 10-10 Me. [OH-] = 1.0 x 10-7 M

Answers

Answer:

[H3O+] = 1.0 x 10-10

Explanation:

A basic solution is any solution whose pH is above 7.0.

If we carefully calculate the pH of each of the species listed among the options, we will discover that it is only [H3O+] = 1.0 x 10-10 that has a pH of 10.0. This pH corresponds to a basic solution. Hence the solution having [H3O+] = 1.0 x 10-10 is a basic solution.

Good's buffers are compounds that are useful near neutral pH. MES buffer has pKa of 6.15, MOPS has pKa of 7.5, and HEPPS has pKa of 8.0.Required:Identify which Good's buffers are most effective near pH 7.0 and near pH 6.0.

Answers

Answer:

MES for pH near to 6.0 and MOPS for pH near to 7.5.

Explanation:

Hello,

In this case, given that the Henderson-Hasselbach equation is:

[tex]pH=pKa+log(\frac{[Base]}{[Acid]} )[/tex]

Good's buffers are those having pKa's near to the required pH since we look for a [Base]/[Acid] ratio to approach 1, thus, for a pH near to 7.0 a good buffer may be MOPS as it has a pKa of 7.5 and for a pH neat to 6.0 a good buffer may be MES as it has a pKa of 6.15.

Best regards.

A farmer applies 1455 kg of a fertilizer that contains 10.0% nitrogen to his fields each year. Fifteen percent (15.0%) of the fertilizer washes into a river that runs through the farm.If the river flows at an average rate of 0.175 cubic feet per second, what is the additional concentration of nitrogen (expressed in milligrams of nitrogen per liter) in the river water due to the farmer's fertilizer each year?

Answers

Answer:

the additional concentration of nitrogen in the water = 0.1396 mg/L

Explanation:

Given that a farmer uses 1455 kg of fertilizer → 10% nitrogen

15% of the fertilizer is said to be washed into the river,

i.e.

(15/100) × 1455 = 218.25 kg

The amount of  nitrogen molecule in the washed fertilizer is :

10%  of 218.25 kg

= (10/100) × 218.25 kg

= 0.1 × 218.25 kg

= 21.825 kg in a year.

The river flows at an avg. rate of 0.175 ft³/sec

Then the amount of river water in a year = [tex]0.175 \dfrac{ft^3}{sec}\times 3.155 \times 10^7 \ sec[/tex]

since 1 ft³ = 28.3168 L

the amount of river water in a year = [tex]0.175(28.3168)\times 3.155 \times 10^7 \ L[/tex]

the amount of river water in a year = 156344132

The concentration of nitrogen molecule= mass/volume

= [tex]\dfrac{ 21.825 \times 10^6 \ mg}{ 156344132 \ \ L }[/tex]

= 0.1396 mg/L

Thus, the additional concentration of nitrogen in the water = 0.1396 mg/L

what happens when the net forces are the same, do you add or subtract it

Answers

Answer:

If two forces act on an object in the same direction, the net force is equal to the sum of the two forces.

Explanation:

google is my explanation

Answer:

Answered by Oreo!

Explanation:

So a net force is the sum of all forces acting on an object! The question u asked is if the net forces are the same, do u add or subtract it.. <= the answer to that would be:

If it’s the same than the net force is the sum of the forces...

The net force = to the sum of two forces

Hope this helps! Sorry if something didn’t go right, I’m new to brainly! :)

Based on Chromium's position on the periodic table, which statement describes the element
chromium (Cr), atomic number 24?
A. chromium is a nonmetal and therefore a good conductor of heat and electricity
B. chromium is a metal that is more reactive than potassium
C. chromium is a metal that is less reactive than sodium
D. chromium is a noble gas that is not reactive

Answers

Answer:

C. chromium is a metal that is less reactive than sodium.

Explanation:

Hello.

In this case, since chromium is in period 4 group VIB we infer it is a transition metal which slightly reacts with acids and poorly reacts with oxygen and other oxidizing substances. Thus, in comparison with both sodium and potassium which are highly reactive even with water as they get on fire, we can say that it is less reactive than both potassium and sodium, therefore, answer is: C. chromium is a metal that is less reactive than sodium.

Best regards.

Question 3 of 10
Which of the following is an example of a phase change from liquid to solid?
A. Ice melting
B. Water freezing
C. Water evaporating
D. Water condensing

Answers

Answer:

the answer is B

Explanation:

B is the answer

The awnser is b water freezing

PLEASE HELP WILL MARK BRAINLIEST!!!!!!!!

Answers

Explanation:

1. 4×10^5

2. 6×10^-4

3. 2.1995×10^7

4. 5.050×10^-2

5. 7280

6. 0.00003608

7. 940.9

8. 0.0015

Marks as brainest

Answer:

not  sure

Explanation:

Determine the identity of an unknown element X using the given table and following clues:

I) Element X is a solid

II) Element X will bond ionically with element O in a 1:1 ratio.

III) As a positive ion, it will have the same number of electrons as argon.

A) calcium
B) chlorine
C) potassium
D) sulfur

Answers

Answer:

calcium

Explanation:

A reaction in which A, B, and C react to form products is zero order in A, one-half order in B, and second order in C.

a. Write a rate Jaw for the reaction.

b. What is the overall order of the reaction?

c. By what factor does the reaction rate change if [A] is doubled (and the other reactant concentrations are held constant )?

d. By what factor does the reaction rate change if [B] is doub led (and the other reactant co ncen trati ons are held consta nt )?

e. By what factor does the reaction rate change if [C] is doubled (and the other reactant concen trations are held constant)?

f. By what factor does the reaction rate change if the concentrations of all three reactants are doubled?

Answers

Answer:

a. [tex]r=k[B]^{1/2}[C]^2[/tex]

b. [tex]Order=3.5[/tex]

c. It does not affect the rate.

d. [tex]\sqrt{2}[/tex].

e. 4.

f. 4[tex]\sqrt{2}[/tex].

Explanation:

Hello,

In this case, considering the given information, we have:

a. [tex]r=k[B]^{1/2}[C]^2[/tex]

b. By adding 1/2 and 2 (powers for B and C), the overall order is:

[tex]Order=\frac{1}{2} +2\\\\Order=3.5[/tex]

c. It is not changed, since the concentration of A is not affecting the rate due to its specific zeroth-order.

d. In this case, if the concentration of B is doubled, such term in the equation shows:

[tex]\sqrt[n]{x} \frac{r_f}{r_i}=\frac{[2B]^{(1/2)} [C]^2}{[B]^{(1/2)}[C]^2} \\\\\frac{r_f}{r_i}=\frac{[2B]^{(1/2)}}{[B]^{(1/2)}}\\\\\frac{r_f}{r_i}=(\frac{2}{1})^{1/2}\\\\r_f=\sqrt{2} r_i[/tex]

It means that the rate increases by a factor of [tex]\sqrt{2}[/tex].

e. In this case, if the concentration of C is doubled, such term in the equation shows:

[tex]\frac{r_f}{r_i}=\frac{[B]^{(1/2)}[2C]^2}{[B]^{(1/2)}[C]^2} \\\\\frac{r_f}{r_i}=(\frac{[2C]}{[C]})^{2}\\\\\frac{r_f}{r_i}=(\frac{2}{1})^{2}\\\\r_f=4r_i[/tex]

It means that the rate increases by a factor of 4.

f. In this case, if the concentration of both B and C are doubled, such terms in the equation shows:

[tex]\frac{r_f}{r_i}=\frac{[2B]^{(1/2)}[2C]^2}{[B]^{(1/2)}[C]^2} \\\\\frac{r_f}{r_i}=\frac{2^{(1/2)}2^2}{1^{(1/2)}1^2} \\\\\frac{r_f}{r_i}=4\sqrt{2} \\\\r_f=4\sqrt{2} r_i[/tex]

It means that the rate increases by a factor of 4[tex]\sqrt{2}[/tex].

Best regards.

what is the molar mass of PbCO₄

Answers

Answer:

283.211

Explanation:

Using the tools and knowledge of science to solve a problem or build new technology is called...

Answers

Answer:

Invention

Explanation:

Scientific ideas can be applied in novel was to solve new scientific problems and create new technology. This process helps to make life easier and better.

The application of scientific knowledge to solve new problems and create new technology is generally referred to as invention.

Hafnium (Hf) has six naturally occurring isotopes: 0.16% of 174Hf, with an atomic weight of 173.940 amu; 5.26% of 176Hf, with an atomic weight of 175.941 amu; 18.60% of 177Hf, with an atomic weight of 176.943 amu; 27.28% of 178Hf, with an atomic weight of 177.944 amu; 13.62% of 179Hf, with an atomic weight of 178.946 amu; and 35.08% of 180Hf, with an atomic weight of 179.947 amu. Calculate the average atomic weight of Hf.

Answers

Answer:

178.463 amu

Explanation:

Average atomic weight of Hafnium is calculated as follows;

[(0.0016 × 173.940) + (0.0526 × 175.941) + (0.186 × 176.943) + (0.2728 × 177.944) + (0.1362 × 178.946) + (0.3508 × 179.947)] =0.278 + 9.234 + 32.911 + 48.543 + 24.372 + 63.125 = 178.463 amu

Therefore, average atomic weight of Hafnium is 178.463 amu

water is denser than oil. When frozen, the oil sinks to the bottom. Why?

Answers

Answer: When water freezes it gets larger and becomes a solid but it still weighs the same as when it was a liquid form. When it becomes larger it takes up space but makes it less dense. Ok so getting to the point- oil unlike water becomes more dense when frozen so this is why oil sinks in water. Sorry if this was confusing but I hope it helped have a great day and god bless you :3

Which of the following species is the least nucleophilic?A) (CH3)3NB) BF3C) H2OD) (CH3)3CO-E) CN-

Answers

Answer:

BF3

Explanation:

BF3 possesses an open sextet. This implies that the octet around the central atom is incomplete. As a result of this, BF3 will function as an electrophile rather than as a nucleophile.

Hence of all the compounds listed in the options, BF3 is the least nucleophillic.

unit processes in charge of smelting​

Answers

Answer:

Smelting, process by which a metal is obtained, either as the element or as a simple compound, from its ore by heating beyond the melting point, ordinarily in the presence of oxidizing agents, such as air, or reducing agents, such as coke.

Hope I helped!

Explanation:

Theories in science can be disproved through new or extended research.
1. True
2. False

Answers

Answer:

True

Explanation:

This is true because technology advances all the time and even Newton's "Laws" could be disproved in the future.

Answer:

True

Explanation:

Based on new research we find out new things

Which phrase is evidence of the limits of what science can study?

Answers

This question is incomplete; here is the complete question:

Which phrase is evidence of the limits of what science can study?

A. Only a phenomenon that a scientist can observe with instruments

B. Only a phenomenon that a scientist can observe without instruments

C. Only a phenomenon that a scientist will be able to explain with certainty

D. Any phenomenon that a scientist can observe or model

The correct answer is D. Any phenomenon that a scientist can observe or model

Explanation:

Science focuses on phenomena that can be objectively studied or witnessed. This includes any phenomenon a scientist can register using observation, instruments, or that can be represented through models. This is because, through observations or instruments, it is possible to prove the phenomenon occurs and understand how this happens; also, models can represent or recreate the phenomenon itself, which is essential to understand and explain the phenomenon. Moreover, science has an objective focus and due to this, aspects such as personal beliefs that cannot be represented through a model  or be observed are not part of science. According to this, the correct answer is D.

When finding the density of a solid, which situation prevents us from being
able to accurately find the volume displacement?
a) if the solid floats
b) if we use an analytical balance
c) if the solid sinks
d) if we use a graduated cylinder

Answers

Answer:

a) if the solid floats

Explanation:

Hello,

In this case, since the determination of the volume of a solid when submerged in water requires to use an analytical balance to measure the mass, but also it is necessary that the solid sinks in order to completely displace the what in the graduated cylinder which accurately provides the volume of the solid via its scale. Therefore, a draw back is a) if the solid floats since the water is not completely displaced.

Best regards.

How many molecules are in 237 g (about a cup) of water? a. 1513.1 b. 4267 c. 6.02 * 1023 d. 93 * 1024 e. 7.93 * 10 24

Answers

Answer:

7.93E24 molecules of water

Explanation:

determine no. of moles of water: 237 g/18 g/mole H2O= 13.17 moles H2O

13.17 moles H2O x 6.02E23 molecules/mole= 7.93E24 molecules of water

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 7.93×10²⁴  molecules are in 237 g (about a cup) of water. The correct option is option E.

What is mole?

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

number of moles of water=237 g÷18 g/mole

number of moles of water = 13.17 moles

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

molecules of water=13.17 moles x 6.02×10²⁴

molecules of water=7.93×10²⁴  molecules of water

Therefore, 7.93×10²⁴  molecules are in 237 g (about a cup) of water. The correct option is option E.

To know more about mole, here:

https://brainly.com/question/15209553

#SPJ5

Which one correctly lists the compound that has the highest boiling point from each group it belongs to? Group I: SiH 4, SnH 4, CH 4, and GeH 4 Group II: HCl, HBr, HF, and HI Group I: SiH4 and Group II: HF Group I: SnH4 and Group II: HF Group I: SnH4 and Group II: HI Group I: CH4 and Group II: HI Group I: CH4 and Group II: HF

Answers

Answer:

Group I: SnH4 and Group II: HF

Explanation:

In the case of group 14 hydrides, we know that the melting and boiling points of compounds increase down the group. Since the melting and boiling points of compounds increase down the group, SnH4 will have the highest boiling point.

In the case of group 17 hydrides, we know that electro negativity decreases down the group. As electro negativity decreases, so does the magnitude of hydrogen bonding among group 17 hydrides. Hence, HF has the highest boiling point among group 17 hydrides since it has the greatest magnitude of hydrogen bonding between its molecules.

. Answer the following: 7 x 2 = 14

1. Find



1. Find

2/3÷4

Answers

Explanation:

2/3 ÷ 4 = 0.166

I think this should be the answer

Explanation:

[tex] \frac{2}{3} \div 4[/tex]

[tex]make \: 4 \: as \: \frac{1}{4} \: since \: is \: divide[/tex]

[tex] \frac{2}{3} \times \frac{1}{4} [/tex]

[tex] \frac{2}{12} = \frac{1}{6} [/tex]

Hope this is correct and helpful

HAVE A GOOD DAY!

Strontium-90 is radioactive and has a half life of 28.8 years. How much of a 2.90mg sample would be left after 137. years?

Round your answer to 2 significant digits. Also, be sure your answer has a unit symbol.

Answers

Answer:

0.11 mg

Explanation:

From the question given above, the following were obtained:

Half life (t½) = 28.8 years

Original amount ((N₀) = 2.90 mg

Time (t) = 137 years

Amount remaining (N) =?

Next, we shall determine the rate of disintegration (K). This can be obtained as follow:

Rate of decay (K) = 0.693/ half life (t½)

K = 0.693 / t½

Half life (t½) = 28.8 years

Rate of decay (K) =?

K = 0.693 / t½

K = 0.693 / 28.8

K = 0.0241 /year

Finally, we shall determine amount remaining after 137 years as follow:

Original amount ((N₀) = 2.90 mg

Time (t) = 137 years

Rate of decay (K) = 0.0241 /year

Amount remaining (N) =?

Log (N₀/N) = kt/2.3

Log (2.9/N) = 0.0241 × 137 / 2.3

Log (2.9/N) = 3.3017 / 2.3

Log (2.9/N) = 1.4355

Take the antilog of 1.4355

2.9/N = antilog (1.4355)

2.9/N = 27.26

Cross multiply

2.9 = N × 27.26

Divide both side by 27.26

N = 2.9/27.26

N = 0.11 mg

Therefore, the amount remaining after 137 years is 0.11 mg

help me ill give brainliest i need help with a b c d and to see if i got propene and methane right please help :(​

Answers

Answer:Yes, you got it right

Explanation:

Pls give brainliest

Which element has fewer than 4 dots In its Electron dot diagrams

Answers

Answer:Strontium (Sr) and Gallium (Ga)

Explanation:

Strontium (Sr) and Gallium (Ga) are the elements which have fewer than four dots in the electron dot diagrams. Explanation: Electron dot diagrams are the diagrams which represent the valence electrons in an element. The electrons are represented by the dots in these diagrams.

What period is Zn (zinc) in?
O A. 2A
O B. 12
O C. 30
D. 4

Answers

Answer:

D. 4

Explanation:

Which statements are true about triangle ABC and it’s translated image, ABC? Select two options.

Answers

Could you upload a new one with two options??

0.400 mole of sucrose, C 12H 22O 11, contains ________ C atoms.

Answers

Answer:

2.89x10²⁴ atoms of Carbon are contained in 0.400 moles of sucrose

Explanation:

The formula of sucrose is C₁₂H₂₂O₁₁, that means per mole of sucrose you will have 12 moles of carbon. In 0.400 moles of sucrose you will have:

0.400 moles Sucrose * (12 moles C / 1 mole Sucrose) = 4.8 moles of Carbon

To convert moles to atoms you must use Avogadro's number (1 mole contains 6.022x10²³ atoms):

4.8 moles Carbon * (6.022x10²³ atoms / 1 mole) =

2.89x10²⁴ atoms of Carbon are contained in 0.400 moles of sucrose

0.4 mole of sucrose, C₁₂H₂₂O₁₁ contains 2.89×10²⁴ carbon atoms

How to determine the mole of carbon

1 mole of C₁₂H₂₂O₁₁ contains 12 mole of C.

Therefore,

0.4 mole of C₁₂H₂₂O₁₁ will contain = 0.4 × 12 = 4.8 mole of C

How to determine the atoms of carbon

From Avogadro's hypothesis,

1 mole of C = 6.02×10²³ atoms

Therefore,

4.8 mole of C = 2.89×10²⁴ atoms

Thus, 0.4 mole of sucrose, C₁₂H₂₂O₁₁ contains 2.89×10²⁴ carbon atoms

Learn more about Avogadro's number:

https://brainly.com/question/26141731

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