what are the elements in the first period

Answers

Answer 1

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

Answer 2

Answer:

"Hydrogen and Helium". Hydrogen and Helium are the elements of the first period in the modern periodic table.

Explanation:


Related Questions

Which of the following pairs of elements will form covalent bonds with each other? PLEASE HELP

Answers

Answer: Your correct answer is A, because potassuim and bromine form covalent bonds with each other, Also check out nile red he made bromine in his dads garage!-Have a nice day :)

The pair of elements which will form covalent bonds with each other are Si (Silicon) and N (Nitrogen). Hence the correct option is (B).

What is Covalent Bond ?

A covalent bond is a chemical bond that involves the sharing of electrons to form electron pairs between atoms.

These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.

Silicon and nitrogen forms strong covalent bond . This stable covalently bonded material does not readily sinter and cannot be heated over 1850⁰C as it dissociates into silicon and nitrogen.

Therefore, The pair of elements which will form covalent bonds with each other are Si (Silicon) and N (Nitrogen). Hence the correct option is (B).

Learn more about Covalent Bond here ;

https://brainly.com/question/19382448

#SPJ2

What force(s)
might cause a car
to slow down?
Friction
Applying the brakes
Wind
All of the above

Answers

Friction, applying the brakes, and wind

B. Directions: Identify what stage of human
development is being described. Choose
from the list of words inside the box.
ADULTHOOD
INFANCY
BIRTH
1. A child learns to walk, talk
and begin to be more self-sufficient at
this stage
2. A child is completely
dependent on the care of his parents in this
stage.
3. It is the stage that the boys
begin to experience changes in their
voice.
4. Boys and girls gain more
independence from their parents during
this stage.
5. Girls at this stage begin to
menstruate ad are now capable of
giving birth.​

Answers

Answer:

Adulthood = 3 and 5

Infancy = 1 and 4

Birth = 2

Explanation:

10. Which is true of unicellular organisms?
A. They lack cells.
B. They all are eukaryotes.
C. They lack cell differentiation.

Answers

Answer:

a

Explanation:

Answer:

The answer is

B. They all are eukaryotes.

Hope it will help :)

I need help in this questions

Answers

Answer:

just use calculator mannn

The correct answer is H

You have the compound CH4. The first element is a
(metal, nonmetal) and the second element is a
(metal, nonmetal). You would predict that this would form a(n).
(ionic, covalent) bond.

Answers

Answer:

1. Nonmetal

2. Nonmetal

3. Covalent

Explanation:

Methane is the molecule being described in this question. It has a chemical formula of CH4 where four hydrogen atoms are bonded to one central carbon atom. Carbon as well as hydrogen are non-metallic elements, which means that they can only share their valence electrons to form a COVALENT BOND.

A covalent bond is a type of chemical bond in which two atoms share their valence electrons. It occurs between two non-metallic atoms. In this molecule, CH4, carbon and hydrogen share their valence electrons to form a covalent bond.

Question 1 (1 point)
If PV = nRT, then if I increase the amount of moles of a gas in a glass jar,
and the temperature of the gas stays the same,
and volume of a jar obviously stays the same,
what will happen to pressure inside the jar?

Answers

Answer:

The pressure also increases.

Explanation:

As we can see in this equation,

Pressure is directly proportional to the moles of a gas in the glass jar.

Temperature and Volume remains constant.

Hence, if number of moles of a gas increases, the pressure also increase "n" number of times.

Substances that are good conductors of heat and electricity at room temperature usually
have delocalized electrons moving freely from atom to atom. Which type of bonding
occurs in these substances?
O covalent
electric
ionic
metallic
ASAP PLEASEE

Answers

Answer:

the answer is electric

Explanation:

i think so

Which of these factors is involved in earthquake formation?

A. plates getting larger
B. rocks breaking
C. stress that decreases
D. faults that remain stationary

Answers

I’m pretty sure it’s B) rocks breaking but i’m not 100% sure

Answer:

B

Explanation:

Edge 2023

What happens when chlorine solution is added to a solution of sodium bromide?
A)No reaction
B)An explosion
C)Bromine is produced

Answers

Answer:

Sodium chloride is produced

Answer:

b

Explanation:

Is this a balanced equation?​

Answers

Answer:

The equation is not balanced.

Explanation:

The Law of Conservation of Matter is also called the law of conservation of mass or the Lomonosov-Lavoisier Law. This law postulates that "the mass is neither created nor destroyed, it only transforms." This means that the reactants interact with each other and form new products with different physical and chemical properties than the reactants because the atoms of the substances are arranged differently. But the amount of matter or mass before and after a transformation (chemical reaction) is always the same, that is, the amounts of the masses involved in a given reaction must be constant at all times, not changing in their proportions when the reaction ends. . In other words, then the mass before the chemical reaction equals the mass after the reaction. The exception to the rule is nuclear reactions, in which it is possible to convert mass into energy and vice versa.

This is, te law of conservation of matter states that since no atom can be created or destroyed in a chemical reaction, the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products.

Then, you must balance the chemical equation. For that, you must first look at the subscripts next to each atom to find the number of atoms in the equation. If the same atom appears in more than one molecule, you must add its amounts.  

The coefficients located in front of each molecule indicate the amount of each molecule for the reaction. This coefficient can be modified to balance the equation, just as you should never alter the subscripts.

By multiplying the coefficient mentioned by the subscript, you get the amount of each element present in the reaction.

Then, taking into account all of the above, you can determine the amount of elements on each side of the equation:

Left side: 2 hydrogen H and 2 oxygen O  

Right side: 2 hydrogen H and 3 oxygen O

Since the quantity of each element is different on each side of the reaction, the equation is not balanced.

The balanced equation is:

2 H₂O₂ → 2 H₂O + O₂  

Sodium bicarbonate is the chemical name for baking soda. Its chemical formula is NaHCO3. What does the subscript 3 mean?

Answers

Answer:

'3' in NaHCO₃ is the number of moles oxygen in 1 mole of sodium bicarbonate

Explanation:

see above note.

C.  

There Are Three Atoms Of Oxygen In Sodium Bicarbonate.

_______

I Got It Right On The Test, Hope It Helps :)

which of the following best explains why the strings of a harp make sounds when it is played?

Answers

Each time the soundboard rises it is pushing air, creating pressure waves. The air right around the harp is pushing on the air that is a bit further away

R4te me for 10 points and be honest with me PLEASE

Answers

Answer:

id give you and 8 or 9 but you are really pretty tho

Explanation:

i give you an 7 i am being honest i was gonna give you a 6 but then your hair is pretty

Is this a redox reaction? give evidence (many points plz answer)
2Mg + CO2 → 2MgO + C

Answers

Answer:

[tex] \boxed{yeah}[/tex]

Explanation:

[tex]CO_2 \: is \: reduced \: to→C \: by \: 2M_g \: (the \: reducing \: agent): while \\ 2M_g \: is \: oxydized \: to→2M_gO \: by \: CO_2 \: (the \: oxydizing \: agent)[/tex]

xam
What do we
call the type of
reflection in
the upper
image?
A. Diffuse reflection
B. Rough reflection
C. Specular reflection
D. Obtuse reflection

Answers

Answer:

Specular reflection is correct answer by my views

hope it helps you

14. Triple bonds are the strongest, followed by double bonds and single

bonds are the weakest.

Explain this trend using electric force and Coulomb's Law in your

answer.

Answers

Answer:

See explanation

Explanation:

Recall that according to Coulomb's law, energy is inversely proportional to the  square of the distance separating the charges. This implies that the smaller the distance of the charges apart, the greater the magnitude of energy.

Similarly, the bond energy of a bond is inversely proportional to the bond length of the bond. The shorter the bond length of the bond, the greater the bond energy.

Triple bonds are shorter than double bonds and double bonds are shorter than single bonds. This implies that triple bonds, having the shortest bonds, also has the highest bond energy and single bonds having the longest bond length, has the lowest bond energy.

Copper (II) nitrate, Cu(NO3)2, solution reacts with potassium hydroxide, KOH, to form a blue
precipitate of copper (IT) hydroxide.
Write the balanced chemical equation:
Write the overall ionic equation:
Identify the spectator ions:
Write the net ionic equation:

Answers

Answer:

Copper(II) nitrate and potassium hydroxide are soluble ionic compounds, which implies that they dissociate completely when dissolved in water to produce ions. ... You can thus say that the balanced chemical equation that describes this double ... Cu(NO3)2(aq)+2KOH(aq)→Cu(OH)2(s)⏐⏐↓+2KNO3(aq).

Which has a larger impact on change in atomic size: moving down one period or moving across a family

Answers

Answer:

hi this my first day, also the answer is moving one period :)

can someone please explain to me the difference between oxidation and reduction? Please I need help.​

Answers

Answer:

Oxidation occurs when a reactant loses electrons during the reaction. Reduction occurs when a reactant gains electrons during the reaction.

Why aren't acid-base reactions considered redox reactions, even though they involve the transfer of hydrogen atoms?

Answers

Answer:   Acid/base and precipitation reactions almost always are NOT redox reactions. For redox to have happened, the number of electrons that an element has must change (i.e. its oxidation state must change). ... But the hydrogen ion never "has" any electron throughout the process and remains in a +1 oxidation state.

Explanation:

let me know if that helped...(☞゚ヮ゚)☞

Acid-base reaction is not a redox reaction, since the oxidation number remains unchanged in acid-base reaction.  

What is acid-base reaction?

An acid-base reaction is the chemical reaction that occur when acids and bases react together.

What is redox reaction?

Redox reaction is a reaction that involves the transfer of electrons between the atoms, ions, or molecules.

Acid-base reactions involve the transfer of hydrogen ions between reactants. Redox reactions involve a change in oxidation number for one or more reactant elements.

Redox reactions involve a change in oxidation number for one or more reactant elements.

Acid-base reactions involve a transfer of a hydrogen ion instead of an electron and the transfer of an H+ ion leaves the oxidation numbers unaffected.

To learn more about acid-base and redox reaction here

https://brainly.com/question/21892598

#SPJ2

What is the temperature in kelvin of a gas if it is allowed to expand from 1.50 L to 4.50 L? The initial temperature is 10.0°C and pressure is constant throughout the change.
Which equation should you use?

StartFraction V subscript 1 over T subscript 1 EndFraction equals StartFraction V subscript 2 over T subscript 2 EndFraction.

T subscript 2 equals StartFraction V subscript 1 over V subscript 2 EndFraction T subscript 1.

T subscript 2 equals StartFraction V subscript 2 over V subscript 1 EndFraction T subscript 1.

Answers

Answer:

first question is the third option and the second question is 849K.

Explanation:

Answer:

third option

849K

Explanation:

Charles Darwin's theory of evolution describes how species evolve due to natural selection. Which of these is NOT evidence of natural selection? A. Carmels have long, bushy eyelashes. B. Mint plant varieties are crossed to express desirable traits. C. The snowshoe here is white in winter and brown in summer. D. Galapagos finches have stronger breaks after years of drought. ​

Answers

Answer:

b

Explanation:

mint plant varieties are crossed to express desirable traits

2. A pharmaceutical chemist runs a chromatography test on a substance
and identifies two of its components by comparing their Ry values
against certain standards. If the two components have Rf values of 1.0
and 0.41, and the solvent front has travelled 12.0 cm from the sample's
origin, what is the separation distance on the chromatogram?

Answers

Answer:

7.08 cm

Explanation:

For number 1;

Rf = d1/d2

d1/12 cm

Rf = 1.0

d1 = 12 * 1

d1 = 12.0 cm

For number 2

Rf = d1/d2

Rf = 0.41

0.41= d1/12

d1 = 0.41 * 12

d1 = 4.92 cm

Separation distance= 12.0 - 4.92 = 7.08 cm

Which statement describes asexual reproduction but not sexual
reproduction?
A. Offspring are genetically identical to the parent.
B. The process involves cell division by meiosis.
c. Offspring are genetically different from one another.
D. The process involves two parents.
Plz i’ll give brainless plz pick correct

Answers

Answer:

A. Offspring are genetically identical to the parent.

That's the answer. I hope it helps!

The statement which describes asexual reproduction but not sexual

reproduction is A. Offspring are genetically identical to the parent.

What is Asexual Reproduction ?

Asexual reproduction is a type of reproduction that does not involve the fusion of gametes or change in the number of chromosomes.

The offspring that arise by asexual reproduction from either unicellular or multicellular organisms inherit the full set of genes of their single parent.

An Asexual reproduction means that the parent organism will simply split into two child organisms, and that there will be no mixing of the DNA, as it is the case in case of the sexual reproduction which mixes up the DNA.

Therefore the child and the parent organism will contain exactly the same genetic material - the correct answer is A.

learn more about reproduction here ;

https://brainly.com/question/14329745

#SPJ6

Put this equation into word form.

Answers

Answer:

2

Explanation:

symbol of postassium is k and there is no symbol k. so i guess no2

If 2.0 moles of magnesium hydroxide are present, how many moles of phosphoric acid, would be required for the reaction?
3Mg(OH)2 + 2H3PO4 Mg3(PO4)2 + 6H2O

Answers

Answer:

1.33

Explanation:

Please help me fast... ​

Answers

B) 1 and 3

it's the right answer

Answer:

For 3rd question, the answer is option D

1. Which of the following statements is true about seeds?
a. Every plant produces seeds.
c. All seeds are good to eat.
b. All fruits contain many of seeds. d. all seeds has young plant, stored food and a seed coat.
2. Flowers cannot usually produce seeds unless
a. they are visited by insects.
c. they produce nectar.
b. they are on plants growing in good soil. d. the right pollen is placed on their stigmas.
3. Fertilization take place before a seed develops. Which statement describes when fertilization
occurs?
a pollen grain falls on a pistil
c. sperm in a pollen joins with an egg cell in an ovule
b. a pollen tube enters an ovary
d. an ovary becomes a fruit
4. Which of the following is NOT a factor needed by plants?
a. fire
b. nutrients

Please pasagot po ng tanong ko please
c. sunlight
d. water
5. Which is the reproduction in plants where the male and female parts of the flower are involved?
a. asexual
b. sexual
c. rhizome
d. pollination​

Answers

Answer:

1 ans:  d. all seeds has young plant, stored food and a seed coat.

2 ans: d. the right pollen is placed on their stigmas

3 ans: a. pollen grain falls on a pistil

4 ans: a. fire

5 ans: b. sexual

Hope it helps,

Please mark me as brainliest

Thank you...

The amount of space that a gas takes up is its
a.
volume.
b.
mass.
c.
pressure.
d.
density.

Answers

Answer:

A. volume............

Answer:

Volume is correct

Explanation:

give the other person brainliest :>

Other Questions
Find the value of x in 4000(1.5^x) = 25,000. Show your work. Due in 20 mins i have know idea Based on the context clues in the sentence, what does the word supine mean Write an equation in slope-intercept form. Which statement best identifies the central idea of the paragraph?A. Pei was not afraid of what other people thought of his ideas.B. Pei changed his ideas based on what other people thought.C. Pei only worked on major, expensive projects.D. Pei's favorite design was the Grand Louvre in Pari Your teacher has won a million dollars in the lottery. Write a five sentence paragraph advising what she should and/or shouldn't do with the money. juego de pelotas similares find the length of the missing side round 2.844 correct ton1 decimal place I need help. So it says to find the shaded area, and I'm not really good a things like this "Never let anyone tell you that you are not good enough to do something." - Will Smith -What does this quote means? There are 30 female performers in a dance recital. The ratio of men to women is 4:5. How many men are in the dance recital? what do you call a material which is capable of reducing friction when applied between moving parts? List two examples of liquid to solid solution. Tom wants to invest $500. He invests in a company that predicts his investment will double in value every 3 years. This situation can be modeled by thefunction f(x) = 500 -23 where x represents the number of years Tom leaves his money with the company. Which graph models this situation? What is the answer to this question Sally collected 32 coins. The ratio of Sallys coins to Bills coins is 4 : 7. If Sally and Bill each double the number of coins they have now, what is the ratio of Sallys coins to Bills coins? there are 12 boys than girls in a class of 60 find the number of boys and girls Check all prism measurements that fit these criteria. All lengths are given in feet. describe briefly the potential energy it has ( roller coaster)