why is
helium number 2 (the second element)
and beryllium number 4 (the fourth
element) on the periodic table ?

Answers

Answer 1

Answer:

See note in Explanation

Explanation:

The modern periodic table of the elements is arranged in order of increasing atomic numbers which is also in terms of the number of protons in the nucleus. That is, for any element listed on the periodic table its atomic number equals the number of protons in the nucleus. Thus, the element with 2 protons in its nucleus would be element #2 (Helium), element #3 (Lithium) has 3 protons in its nucleus and element #4 (Beryllium) has an atomic number 4 and contains 4 protons in its nucleus.

Also, this arrangement of elements finds that elements below elements 2, 3 & 4, Neon #10; sodium #11 & magnesium #12 have similar chemical and physical properties as does elements #2, #3 & #4. Such gives rise to the 'Periodic Law' => the chemical and physical properties of the elements is a periodic function of their atomic number (or, number of protons in the nucleus).


Related Questions

________ is the enthalpy change when 1 mole of a substance is formed from its elements under standard conditions.

A. ΔHθc
B. ΔHθn
C. ΔHθf
D. ΔHθa

Answers

The correct answer is C

The correct answer is C. ΔHθf

We define the standard enthalpy of formation as the enthalpy change when one mole of a substance is formed from its elements under standard conditions. The standard conditions are 1 atm pressure, 273 K temperature and 1 M concentration.

The standard enthalpy of formation is denoted using the symbol ΔHθf.

Hence, ΔHθf is the enthalpy change when 1 mole of a substance is formed from its elements under standard conditions.

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Proteins are

A) built in the nucleus by DNA and transported to the ribosomes.


B) converted from nucleic acids to amino acids in the nucleolus.


C) made on ribosomes and then transported to golgi appartus.


D) created in the nucleus and then shipped to the parts of the cell where they are needed

Answers

Answer:

I would say B

Explanation:

If I'm wrong I apologize, have a good day

[tex] \huge \mathfrak \red{hello...}[/tex]

[tex] \blue{The \: correct \: answer \: is \: (C).}[/tex]

Thanku...

The southern United States experiences periodic occurrences of severe cold and drought conditions. Which weather phenomenon most likely causes this and why?

Answers

The southern United States experiences periodic occurrences of severe cold and drought conditions. Which weather phenomenon most likely causes this and why? La Niña, because the jet stream is displaced southwards. La Niña, because the jet stream is displaced northwards.

The weather phenomenon that most likely causes periodic cold is:

La Nina

This is caused by the:

Jet stream which moves to the south side

In the Southern United States, there is a weather phenomenon which occurs when there is only a periodic occasion of severe cold. This happens because of what is called La Nina that occurs as a result of the movement of the jet stream.

Read more here:

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Calculate the mass of .0605 moles of crystalline sucrose. Sucrose is C12 H22 O11 . The molar mass is __________ g/mole. Show your work below and record your answer.

Answers

Answer:

20.7g/mol

Explanation:

Explain the horizontal periodic trend

Answers

Answer:

Trends on the Periodic Table have a vertical component and a horizontal component. Vertical trend: as more “shells” are added to the electron cloud, it expands. Horizontal trend: if atoms have the same number of “shells”, atoms with more protons will draw the electron cloud in tighter.

Explanation:

How many oxygen atoms are there in 5 molecules of Al2(SO4)?

Answers

Answer:

There are two aluminum ions and three sulfate ions; or two aluminum, three sulfur, and twelve oxygen atoms.

Explanation:

In 5 molecules of Al₂( SO₄ ) there are 20 oxygen atoms are present. In  one molecule of aluminum sulphate there are 4 oxygen atoms present and in 5 molecules of  Al₂( SO₄ )  20 oxygen atoms present.

What is molecule ?

According to the environment, the word may or may not include ions that meet this requirement. A molecule is a collection of two or more atoms bound together by the attractive forces known as chemical bonds.

There are three different kinds of molecules: atom-sized molecules, element-sized molecules, and compound-sized molecules.

A molecule is the smallest unit of any material that is composed of one or more elements and is capable of existing independently while maintaining all the substance's physical and chemical characteristics. Further atom division occurs within molecules.

Thus, In 5 molecules of Al₂( SO₄ ) there are 20 oxygen atoms are present.

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Identify the reaction type shown and describe the clues that were used to identify it. Fe2O3 + 2SiO2 → Fe2Si2O7

Answers

The type of reaction of Fe2O3 + 2SiO2 → Fe2Si2O7 would be that it is a synthesis reaction. It is a type of chemical reaction in which two or more simple substances combine to form a more complex product.

Answer:

The type of reaction of Fe2O3 + 2SiO2 → Fe2Si2O7 would be that it is a synthesis reaction. It is a type of chemical reaction in which two or more simple substances combine to form a more complex product. Hope this answers the question. 

Explanation:

The force of gravitational attraction between two objects depends on the distance between the objects and their_____ 1. Buoyancies 2. Temperature 3. Masses 4. Shapes

Answers

Answer:Newton's law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them.

Objects with greater mass have a stronger force of gravity between them. ...

Objects that are closer together have a stronger force of gravity between them.

Explanation:

hope it helps

Answer:

masses

Explanation:

SHOW WORK
A hummer weighs 3.2 tons, what is the weight in pounds (lbs)?

Answers

1 ton = 2000 pounds

3.2 times 2000 = 6400 pounds

you must convert the tons to pounds which is why you multiply and not do any other operations .. Hope fully that is helpful !!

TOPICAL ASSINMENT 2
1. If 25cm' of O.IM H,SO, solution neutralised a solution containing 1.06g anhydrous sodium carbonate in
250cm. of solution, calculate the molarity and the volume of the sodium carbonate solution used. (3mks)​

Answers

The molarity = 0.04 M

The volume = 6.25 ml

Further explanation

Given

25cm³ of 0.1 M H₂SO₄

1.06g Na₂CO₃ in  250cm³ of solution

Required

the molarity and the volume of Na₂CO₃

Solution

Molarity of  Na₂CO₃ :

[tex]\tt \dfrac{1.06/106~mol}{0.25~L}=0.04~M[/tex]

Reaction

H₂SO₄ + Na₂CO₃ ⇒Na₂SO₄ + H₂O + CO₂

mol H₂SO₄ = 25 x 0.1 = 0.25 mlmol= 2.5 x 10⁻⁴ moles of  Na₂CO₃

The volume of solution used :

[tex]\tt V=\dfrac{n}{M}=\dfrac{2.5.10^{-4}}{0.04}=6.25.10^{-3}~L=6.25~ml[/tex]

hey what's the value of pi till
5 digits after decimal​

Answers

Answer:

Pi to 5 decimals is 3.14159-

Brainlist pls!

P.S. It's a repeating number, but you can just put a (-), so that you don't have to type the whole thing out.

Answer:

sorry raaz report mat kerna

points collect kr rehe hai

Helpppp
Which of these is the BEST
description of extinction?

Answers

Answer:

d

Explanation:

chemical formula for tin iv carbide

Answers

Answer:

Explanation:

Sn(WC)2

if it is tungsten carbide this should be correct but there are many versions of carbide

Sn(MC2)2

could also be possible

the 2 next to MC should be a subscript

Which group of elements will completely fill their s and p valence subshells?

Answers

Answer:

Nobel Gases will have a full p valance shell aswell as a s subshell

Explanation:


Which of the following statements about nonmetal elements is true?


A.) Nonmetal elements are stronger than metals.

B.) Nonmetal elements are never used in computers.

C.) Nonmetal elements are sometimes cheaper to make.

D.) Nonmetal elements are used only in laptop computers.

Answers

Answer:

C

Explanation:

The statement which is true about non-metal elements is as follows:

Nonmetal elements are sometimes cheaper to make.

Thus, the correct option for this question is C.

What are Non-metals?

Non-metals may be defined as those chemical elements that significantly lack the attributes of metals. They generally range from colorless gases to shiny and high melting point solids. Some examples of non-metals include boron, carbon, nitrogen, etc.

Non-metals are not stronger than metals because the arrangement of bonds in metals is highly compacted. Non-metals are very frequently utilized in the manufacture of computers, laptops, and other electronic devices along with metals. But most of the time non-metals are cheaper to synthesize.

Therefore, non-metal elements are sometimes cheaper to make is a statement that is true about non-metal elements. Thus, the correct option for this question is C.

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What does dehydration cause?

Answers

Dehydration can lead to a loss of strength and stamina. It's a main cause of heat exhaustion. You should be able to reverse dehydration at this stage by drinking more fluids. If dehydration is ongoing (chronic), it can affect your kidney function and increase the risk of kidney stones.

[I copied this from the internet, but hope this helps!]

Dr. Murrays science class recently read about an experiment that had surprising results. The decided to perform the experiment in their class, but they used more advanced methods. Their results

Answers

The question is incomplete, the complete question is;

Dr. Murray's science class recently read about an experiment that had surprising results. They decided to perform the experiment in their class, but they used more advanced methods. Their results

must be completely different, but they are more reliable.

could be the same as before, or they could be completely different.

must be the same as the recorded results, but they are more reliable.

could be the same as the recorded results, or they must be inconclusive.

Answer:

could be the same as before, or they could be completely different.

Explanation:

Now we know that in carrying out a scientific research, there is such a thing as replication.

Replication means that other scientists in other places carry out the same experiments previously done and expect to obtain the same results as the first time the experiment was done.

However, this is not a case of replication because a different and more advanced method was used in the experiment. Once the methodology of the experiment has been changed, then the results could be the same or different. Hence the answer above.

an object with a mass of 300 kg is observed to accelerate at the rate os 4m/s² what is the total force required

Answers

Answer:

75 Newton

Explanation:

In order to find the force of the object, you must remember that the equation N = (mass x acceleration). Therefore meaning you would divide 300 kilograms, the mass, by 4 meters per second (squared), the acceleration.

Who discovered phosphate?

Answers

Answer:

Hennig Brand

Explanation:

What type of bond is formed between sodium and sulfur

Answers

Answer:

The Bond would Be ionic

Explanation:

Thier electronegativites are way to differnt so Sulfur would steal from Sodium

hey martin991 im sorry i just realized that was a dif account please forgive me plz help me and HAPPY NEW YEAR ♧
Energy stored in the bonds between atoms is called
A.kinetic energy.
B.mechanical energy.
C.chemical energy.
D.thermal energy.

Answers

Answer:

A. Kinetic energy

Explanation:

Kinetic energy is stored in the bonds between atoms.

2) If 100.0 J of heat are added to 20.0 g of water at 30.0°C, what will be the final
temperature of the water? What would the temperature be in Kelvin?

Answers

The final temperature of the water will be 31.2 °C... i don’t know the second one sorry :(

Can anyone explain this to me?

Answers

The answer is D, the definition of standard enthalpy of formation is as follows: when one mole of a substance in the standard state (1 atm of pressure and 298.15 K) is formed from its pure elements. The last two words being especially important to this question. We would rule out A, B and C all because the product is formed from a mixture of an element and a compound and not just of elements. In other questions the reactants may all be in elemental form so you must look at the products being one mole or the reactants not being in their standard state.

Please help me!!!!!!!!!!!!!!

Answers

Higher energy of reactants, state of transition , lower energy of product

What can happen when tectonic plates move a few centimeters?
A. The atmosphere can become cooler.
B. Whole continents can move.
C. The ozone layer can thicken.
D. The moon can move closer to Earth.

Answers

Answer: B. Whole continents can move

Explanation:

Answer:the answer is b Whole Contenints can move

Explanation:took the test and got it right

Why does the complete combustion of methane and octane produce the same product?E

Answers

Answer:

Because they are both of the same functional groups (alkane)

how are molecules, mixtures, and pure substance related

Answers

Answer:

Pure substances are further broken down into elements and compounds. ... A chemical substance is composed of one type of atom or molecule. A mixture is composed of different types of atoms or molecules that are not chemically bonded.

Explanation:

Balance the following chemical
equation by providing the correct
coefficients.
[? ]FeBr3 + []Na2S → Fe2S3 + NaBr

Answers

Do you need any explanation regarding how I got those numbers?

Answer:

2FeBr₃   +    3Na₂S  →   Fe₂S₃  +  6NaBr

Explanation:

The expression to be balanced is given as:

        FeBr₃   +    Na₂S  →   Fe₂S₃  +  NaBr

To balanced this chemical equation, we can use a simple mathematical approach.

Simply use the alphabets a, b, c and d to represent the numbers that will make the equation balanced;

        aFeBr₃   +    bNa₂S  →   cFe₂S₃  +  dNaBr

Conserving Fe;

                   a  = 2c

Conserving Br;

                    3a  = d

Conserving Na;

                    2b = d

Conserving S;

                    b = 3c

Let a  = 1,      b  = [tex]\frac{3}{2}[/tex]

      c  = [tex]\frac{1}{2}[/tex]      d = 3

 Multiply through by 2 to get whole number ratios;

        a  = 2, b  = 3 , c = 1 and d = 6

          2FeBr₃   +    3Na₂S  →   Fe₂S₃  +  6NaBr

 

     

Dry hydrogen chloride was bubbled in methylbenzene and sodium carbonate added . Explain this observation.

Answers

Answer:

No observable change, unless dry hydrogen Chloride reacted in presence of a peroxide (ROOR)

two gasses in the air that cause rusting

Answers

Answer:

oxygen and Hydrogen

Explanation:

Oxygen and Hydrogen causes rusting on metals after combining with moisture

oxygen and hydrogen:D
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In a laboratory, it is often convenient to make measurements in centimeters and grams, but SI units are needed for calculations. Convert the following measurements to SI units. (a) 0.92 cm (b) 141.64g kg (c) 15.8 cm3 m3 (d) 63.6 g/cm3 kg/m3 What is the approximate circumference of the circle shown below What is [(5387x29) + (3255x73)] America's goal for communism was to? 25(x+5\4)^2-16(x7\4)^2 factorize the expression Is x = 3 a solution to the equation below? (substitute and check if they equal each other)2(2x+1)+x=8x+2-3x need step by step explanation Which detail from Through the Looking-Glass is symbolic of the author, Lewis Carroll, being sad to see Alice Liddellgrow up?The White Knight repeatedly falls off his horse.The White Knight asks Alice to wait and wave to him.The White Knight tells Alice he invented a new pudding.The White Knight leaves Alice at the end of the wood. HELP PLEASE!!!!!!!!!!! A period is a hard time in a woman's life they bleed at least 7 days a month and still live! Its amazing what we can do being a girl myself im all about girl empowerment. Anyways my point is its a hard time when your on your period,but have y'all ever wondered what it's like for a homeless woman on her period? But when a homeless woman is on her period she shouldn't have to choose to eat or to buy tampons/pads. Sometimes they have to use toilet paper when there on there period cause period products are expensive. That's why I encourage yall to be thankful for what you have,and if you can donate care packages especially for our homeless woman who really need tampons and pads. If you can and want to do this,here some suggestions of what to put in them; FoodA hairbrushPadsTampons2x bars of soapWash clothsdeodoranta mirrorblanketsTreats for pets if they have thema pocket knifea letter.This stuff will really help homeless people and most of all the woman that can't afford period products. Please don't report I'm trying to raise awareness for homeless people cause as a girl myself I know what it's like. remember be thankful for what you have and never take it for granted. Stay beautiful What is main idea ? What is theme ?What is context clues ?What is Key Details? ahem i will have a list of things you can answer if you want they are kinda funny things not like " 1576534657*231346557+65765-35=?" lol anyway lets get startedwhat do stink bugs eat ( do i really wanna know?)What animals eat human poop? (eww)how many teeth does a human have (um ok?)what do taste buds look like (kinda weird not gonna lie)That't it for now hope you had fun 100 points for the ones who help me and if you answer first you get brainliest 8750.0 has how many significant digits? How can I find the answer for number 1 and 4 with explanation? Which of the following is the best summary of Small Portions? a. Alvarez is misunderstood by her friends. b. Many small pieces make up the human experience. c. Appreciate little things. d. In just one piece of fruit, we can find lifes mLiterary Focus I WILL GIVE BRAINLIEST!!!!!!!! ASAP A pound of apple costs $2.50. Represent the cost of n pounds. Gary's pay is $15 per hour. He receives a 6% pay raise. Solve for y*show your work *6y - 3x = 121/2 x + 1/4 y = 2 can anyone answer this? WHATS THE SLOPE BETWEEN THE POINTS (-2,8) AND (4,20) Steam Workshop Downloader