I am an element in period 4 with 7 valence electrons.​

Answers

Answer 1

Answer:

The elements in this family are fluorine, chlorine, bromine, iodine, and astatine. Halogens have 7 valence electrons, which explains why they are the most active non-metals.

Explanation:

Answer 2

Answer:

Selenium

Explanation:


Related Questions

How many moles of Na2SO4 are present in 426.12 grams of Na2SO4? (5 points)

Group of answer choices

2

3

5

6

Answers

Answer: It’s 2.9 moles

Explanation:

Answer:

b) 3

Explanation:

i got it right

Scientists often need a catalyst to start a chemical reaction. They need to apply heat, acids, or other materials to jump-start the experiment.

Which phrase is the best definition of catalyst?

A. something hot
b. something acidic
c. something that triggers
d.something that is scientific

Answers

Answer:

something that triggers

Explanation:

a catalyst helps move a reaction along

A catalyst shows some specificity in its action. It speeds up only a spontaneous reaction. The best definition of catalyst is something that triggers. The correct option is C.

What is a catalyst?

A substance which increases the rate of a chemical reaction without itself undergoing any permanent change chemically or quantitatively is defined as the catalyst and the phenomenon is called catalysis.

It is believed that a catalyst actually participates in the chemical reaction that is speeds up. It forms temporary bonds with the reactants yielding an intermediate activated complex.

A typical example of catalyst is iron (Fe) which is used in the Haber process for the manufacture of ammonia. The catalyst is recovered unchanged in amount and chemical composition at the end of the reaction.

In most cases, a small amount of a catalyst can speed up reaction between large amounts of reactants. A catalyst shows maximum efficiency at optimum temperature.

Thus the correct option is C.

To know more about catalyst, visit;

https://brainly.com/question/1565029

#SPJ6

According to the Heisenberg uncertainty principle, it is impossible to know both the __ and __ of an electron simultaneously.
a. mass and charge
b. position and velocity
c. mass and position
d. velocity and charge

Answers

Answer:

C

Explanation:

It's simple because there were so many quantitative analysis of error and they didn't had the kind of observations as we have now

1. How many moles of Boron is 1.25 x 1023 atoms of Boron? *
O 0.208 mol B
0 7.53 x 1046 mol B
O 1.35 x 1025 mol B
0 4.82 mol B

Answers

Answer:

0.208 mol B

Explanation:

There are 6.02 × 10^23 atoms in one mole of a substance, according to Avagadro's law.

According to this question, there are 1.25 x 10^23 atoms of Boron. This means that the number of moles in the Boron atom can be calculated thus:

number of moles (n) = number of boron atoms (nA) ÷ Avagadro's number

n = 1.25 x 10^23 ÷ 6.02 × 10^23

n = 0.2076 × 10^(23-23)

n = 0.208 × 10^0

n = 0.208 × 1

n = 0.208 moles of Boron

A2B8 + C2 - B2C + AC2

Answers

Answer:

You need to put more info! If you are trying to find the GCF its 1

Wastewater filtration

Pros and cons of secondary water filtration?

Answers

Pros:
• Water filtration is cost effective, and it does not require a lot of money to maintain
•It is very easy and straightforward to use

Cons:
•Thorough cleaning and care of the equipment is very vital so that they can carry out the water softening process without any hitch whatsoever


“Sewage"; used water from a community (homes, businesses and industries, stormwater runoff)



Type
Pros
Cons
Pitcher
Low upfront cost; no installation needed.
Does not remove all contaminants; filters must be changed every couple of months and will increase the yearly cost of the filter system; filtration is slow.
Faucet/On the Counter
Relatively inexpensive; can switch between filtered and unfiltered water; easy to install; ideal for drinking and cooking water.
Faucet mounted may not fit on all faucets; decreases flow rate; filters are changed every couple of months.



On the counter may require some installation and can take up space; can sometimes be expensive.
Under-sink
Filter system is out of sight; infrequent filter changes; ideal for drinking and cooking water.
Requires installation; can sometimes be expensive; takes up cabinet space.
Whole House
Whole house kept clean from one system; various processes available; if system uses filters they are changed every couple of years.
Professionally installed; very expensive.
Reverse Osmosis
Removes most unwanted contaminants.
5-step process; filters replaced frequently; very expensive; wastes a lot of water.
Distillation
Removes heavy metals, fluorides and bacteria.
Not energy efficient; takes up a lot of space; very expensive.
Ultraviolet (UV)
Does not use heat or chemicals to remove contaminants.
Any color in water will prevent UV from working; sometimes filtration is necessary prior to UV; has a low effectiveness for removing chemicals.

Hope all these helps

How many moles of S2 are needed to produce 1.50 moles of SO2 gas

Answers

Answer:

1.5moles of S;

Explanation:

The reaction expression is given as:

            S +  O₂   →   SO₂

Number of moles of SO₂  = 1.5moles

From the balanced reaction expression:

              1 mole of SO₂ will be produced from 1 mole of S;

  So;      1.5moles of SO₂  will produce 1.5moles of S;

 

 

The moles of S₂ needed to produce 1.50 moles of SO₂ gas is 1.5 mol.

What are moles?

The mole is a SI unit of measurement that is used to calculate the quantity of any substance.

The reaction is

S +  O₂   →   SO₂

The number of moles of SO₂ is 1.50 mol

1 mole of S produce 1 mole of SO₂

Then, 1.5 mole of S will produce 1.5 SO₂

Thus, the moles are 1.5.

Learn more about moles

https://brainly.com/question/20486415

What would be the mass of 3 moles of water molecules?
a
54 grams
b 40 grams
C
30 grams
d 20 grams

Answers

Answer:

[tex]\boxed {\boxed {\sf A. \ 54 \ grams }}[/tex]

Explanation:

To convert from moles to grams, we must use the molar mass.

Recall that water's molecular formula is H₂O. It contains hydrogen and oxygen. Look up the two elements masses on the Periodic Table.

Hydrogen (H): 1.008 g/mol Oxygen (O): 15.999 g/mol

Now, use these masses to find water's mass. The subscript of 2 tells us there are 2 atoms of hydrogen, so we multiply hydrogen's mass by 2 and add oxygen's.

H₂O= 2(1.008 g/mol) + 15.999 g/mol = 18.015 g/mol

Use the molar mass as a ratio.

[tex]\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]

Multiply by the given number of moles.

[tex]3 \ mol \ H_2O*\frac{18.015 \ g \ H_2 O}{ 1 \ mol \ H_2 O}[/tex]

The moles of water will cancel.

[tex]3 *\frac{18.015 \ g \ H_2 O}{ 1 }[/tex]

[tex]3 *{18.015 \ g \ H_2 O}[/tex]

[tex]54.045 \ g \ H_2O[/tex]

Round to the nearest whole number. The 0 in the tenth place tells us to leave the number as is.

[tex]54 \ g \ H_2O[/tex]

There are about 54 grams of water in 3 moles.

Answer:

54 grams

Explanation:

First step is to find what one mole of water is in grams.

Water is H2O so that means we have two moles of Hydrogen.

H - 2 grams (on periodic table)

We have one mole of Oxygen.

O - 16 grams (on periodic table)

Add 2 and 16 to get 18 total grams in one molecule of H2O

Now multiply 3 times 18 to know how many grams in 3 moles of H2O

You end with

3x18=54 grams

How is heat transferred through space

Answers

Heat is transferred by energy waves moving through space. Explanation: According to research: Radiation is the transfer of heat energy through space by electromagnetic radiation. Most of the electromagnetic radiation that comes to the earth from the sun is invisible

Please give brainiest if possible, I kinda need it. Thnx!

Answer:

the transfer of energy through space is called radiation. through radiation there is no direct contact between heat source and object. sunlight radiation warms the earth's surface; radiation can also come from fires.

Why can single bonds rotate freely?

Answers

Carbon atoms in single bonds rotate freely. Rotation can occur because the heaviest electron density in the σ bond exists along an imaginary line between two carbon nuclei. Rotation does not change this electron distribution; the bond strength remains constant throughout rotation.


which element group makes computers and calculators

Answers

electronic or Technology

HELP PLSSSSSS ASAPPPPP

Answers

Based on my knowledge of science so some may be wrong...
My key
Synthesis Reactions = SR
Decomposition Reaction = DR
Single Replacement Reaction’s = SRR
Double Replacement Reactions = DRR
Combustion Reactions = CR
#1 SR
#2 SR
#3 SR
#4 SRR
#5 DRR
#6 SR
#7 DR
#8 DR
#9 sorry not sure
#10 DR
#15 SR

The stability of atomic nuclei is most affected by the
a)number of N
b) number of e
c) number of P
d) ratio of N to P
ASAP PLZZ

Answers

D. Ratio of Neutrons to Protons

V7
Which of the following is a MIXTURE. Select ALL that apply.
(0/1 Point) a:brass
b:calcium
c:sodium chloride
d:apple juice​

Answers

Answer:

sodium chloride

Explanation:

How many molecules of nitrogen dioxide (NO2) can be produced from 4 moles
of oxygen (O2)? *

Answers

The number of molecules of Nitrogen dioxide : = 4.816 x 10²⁴

Further explanation

Given

4 moles of Oxygen(O2)

Required

The number of molecules

Solution

Reaction

2NO + O2 ⇒ 2NO2

From the equation, mol NO2 :

= 2/1 x mol O2

= 2/1 x 4 moles

= 8 moles

The number of molecules :

= 8 x 6.02 x 10²³

= 4.816 x 10²⁴

Someone help it’s due today

Answers

Answer:

All elements are neutral

Explanation:

The plum pudding model of the atom indicated that all elements are neutral. The model was proposed by J.J Thomson after he conducted his experiment on the gas discharge tube.

From the experiment he discovered electrons which he called cathode rays.

Therefore, he suggested the plum pudding model of the atom.

The model describes negatively charge sphere surrounded by positive charges to balance them.

Dana is playing with her friends. They ride their scooters 20 meters down the road North. They stop to grab a drink of water. Feeling tired, they turn around and ride their scooters 20 meters south
What is Dana and her friend’s displacement

Answers

Answer:

what is the displacement

Explanation:

1) How many atoms are in Molecules? O One O Exactly two O Two or more O Compounds don't have atoms​

Answers

Answer:

Two or more!

Explanation:

what type of bond is Cl and Br?​

Answers

Answer: Polar bond

Explanation:

What is the oxidation number for Cl?

2
+1
-1
+2.

Answers

Answer:

-1

Explanation:

If you look on the periodic table it’ll show you it’s -1

The nucleus of an atom contains ________________________________________.

Answers

Answer:

protons(positively charged) and the neutrons (no charge)

Explanation:

Answer:

The nucleus of an atom contains protons and neutrons.

Why are we able to see planets at night?

Answers

Answer:   Because planets do not have nuclear fusion, they do not produce their own light. Instead, they shine with light reflected from a star. When we see planets in the night sky, such as Venus, the so-called "Evening Star," we're seeing reflected sunlight.

Explanation:

nuclear energy is created through the process of splitting apart atoms and releasing large amounts of heat energy that can be converted to electrical energy.this process is known as?

Answers

Nuclear fission is a process by which the nucleus of an atom is split into two or more smaller nuclei, known as fission products. The fission of heavy elements is an exothermic reaction, and huge amounts of energy are released in the process.

When two objects are touching, thermal
energy transfers from...
hotter to colder substances?
Or
colder to hotter substances?

Answers

Answer:

According to the laws of thermodynamics, Molecular movements of particles will tend to move into state of lower energy and this would mean that knowing the vibrational and translational energy of complex molecules will lose and give off energy usually in the form of heat but also sound and other transferable mediums it will tend to become less energetic and this mobile indicative of colder objects, if examining the average Molecular kinetic energy and bond energies of the compounds in question.

True/False: All of the elements combine in a variety of ways to make up all living and all nonliving things

Answers

Answer:

true

Explanation:

How did modern scientists experiment with Van Gogh's paints to determine their chemical reactions?
1. They used X-ray analysis.
2. They used litmus testing.
3. They burned the paint to examine what elements were left after the chromium was burned off.
4. They studied the density of modern yellow paint to that of 100-year-old paint.

Answers

Answer:

I think the answer is A - they used X-ray analysis.

Explanation:

Answer:They used X-ray analysis

Explanation:

It’s in the text

David walks 10 Km North. He turns East and walks 10 more Km. What is his distance

Answers

Answer:

20 km

Explanation:

he walks 10 km + another 10 km so 20 :)

- How many moles of S2 are needed to produce 1.50 moles of SO2 gas? S2 + 20, ----> 2802​

Answers

Answer:

0.75 moles

Explanation:

S2 + 2O2 = 2SO2

From the reaction above,

We see that number of moles attached to S2 is 1 and number of moles attached to SO2 is 2.

Since we want to find how many moles of S2 are needed to produce 1.50 moles of SO2 gas

The answer is gotten by proportion;

Number of moles = 1/2 × 1.5 = 0.75 moles

List four rules for rounding numbers.

Answers

Answer:

the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is 40

If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down. Example: 33 rounded to the nearest ten is 30

Rounding fractions works exactly the same way as rounding whole numbers. The only difference is that instead of rounding to tens, hundreds, thousands, and so on, you round to tenths, hundredths, thousandths, and so on.

By rounding off, you could easily figure out that you would need about $6.00 to pay for your groceries.

How many atoms of silver are in a bracelet that has a mass of 13.94 grams?

Answers

Number of Silver atoms : N = 7.8 x 10²² atoms

Further explanation

Given

mass of bracelet : 13.94 g

Required

Number of atoms

Solution

Assuming the bracelet consists entirely of silver

mol of silver :

= mass : molar mass

= 13.94 g : 107,8682 g/mol

= 0.129

Number of atoms :

N = n x No(No = Avogadro's number)

N = 0.129 x 6.02 x 10²³

N = 7.8 x 10²² atoms

Other Questions
3 left parenthesis x space minus space 8 right parenthesis greater than negative 4 space plus space x How is the proportion of hydrogen to helium in the Sun's core changing over time? How it impact the environment The length l of a 200-square-foot rectangular vegetable garden is 4 feet less than twice the width w. Find the length and width of the garden. slope y interceptx intercept Some one please help me on this I am very much dum How did Georgia citizens provide for troops during WWI? Choose all that apply. A: many georgians served in the war.B: citizens conserved goods.C: georgian's mass produced bullets.D: georgia's cotton was used to make soldiers' uniforms and bandages. Express 432 as a product of powers of its prime factors. Question 2Determine whether the following sentences are written with consistentverb tense and do not need to be changed, or if they are written withinconsistent verb tense and need to be changed.I jumped when I heard the shriek outside; I run to the window to see what happened.a. change happened to happensb. change run to ranC. change heard to heard. no change is needed. dont know how to solve these :l I dont understand this so can I get help H E L P I D O N T K N O W I T Dan's car depreciates at a rate of 13% per year.By what percentage has Dan's car depreciated after 4 years?Give your answer to the nearest percent HELP PLS ILL GIVE BRAINLIESTis that right^ Which would be the best headline for the "News Dispatch" dated July 31, 1862?Press enter to interact with the item, and press tab button or down arrow until reaching the Submit button once the item is selectedA Washington, D.C., Soldier Questioned and Imprisoned for Helping Known SpyB Union Soldiers Divulge Top-Secret Information to Prisoners of WarC Confederate Authorities Seeking Information About Federal Troop MovementsD Virginia Woman Arrested and Jailed for Relaying War Information Factor 8a + 16c using GCF Can someone pls help . I WILL MARK U BRAINLIEST !!!! i dont know how to do this please help Simn Bolvar is one of the independence heroes in many Latin American countries.Panam, Ecuador, Colombia, Venezuela, and of course Bolivia, which was named afterhim, were liberated with Bolvars help.Bolvar was born in Caracas, Venezuela, to a wealthy family. He received a goodeducation and during his youth spent some years in a military academy. He also studiedin Spain and traveled through Europe, where he became acquainted with manyintellectuals of the era. By then he already wanted to see Latin America free from theSpanish crown. Upon his return, he started to fulfill his desire.In 1810 many regions on the American continent declared their independence fromSpain, and Bolvar had a main role in the independence process in various nations. Thisprocess was not easy. There were a series of battles and civil wars, and even a period ofself-exile to Jamaica, but after several years, Bolivar attained independence forVenezuela and Nueva Granada (today Colombia and Ecuador.) Years later, Bolivarhelped the cause for independence in Peru and Alto Peru (today Bolivia.) After theindependence war, Bolivar became president of Nueva Granada and Peru. He is knownas the liberator in these countries.Where was Simon Bolivar born?In which country is Bolivar seen as their hero of independence?where did Bolivar go during exile? When did the battles of independence begin? Find the value of x in the equation 2(x +1)=14