1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Marysya12 [62]
3 years ago
9

Which of the following elements contains 7 valence electrons?

Chemistry
2 answers:
Evgesh-ka [11]3 years ago
7 0

Answer:

Halogens

Explanation:

Because elements can have 8 valence elctrons so noble gas group 18 has 8 valence electrons and previous group before group 18 or noble gas is called Halogens or group 17 whatever you want to prefer periodic table has all of informations

Liono4ka [1.6K]3 years ago
6 0

Answer:

Elements: F, Cl, Br, I, At

Explanation:

Hi there,

When you are trying to find the valence electrons for an element, look at the last number of the electron configuration.

For example, if you want to find the number of valence electrons of Carbon (C), you notice that the electron configuration is<u> 2 - 4.</u>

We know that this element has four valence electrons because the last number in its electron configuration is 4.

For your question, simply find all of the elements that have the number 7 as the last number on its electron configuration on the periodic table.

Hope this answer was helpful. Cheers.

You might be interested in
Why is copper used to make electric wires?​
sesenic [268]

Question:

Copper is used in a variety of applications, one of which is electrical wires. Whether it’s a power cable for a TV, computer, kitchen appliance or construction tool, it’s probably made of copper. Featuring the atomic number 29, this red-brown metal has become essential to our everyday life by helping power countless devices. But copper isn’t the only material that can transmit electricity, so why is it preferred for creating electrical wires?

Answer:

<h2>The two most important factors on why Copper is used to make not just electric wires, but lots of electric related things is that they are Inexpensive and Super Conductive</h2>

Explanation:

Now, I will explain the reasons why these are good things about the copper wire.

<h2>High Conductivity </h2>

Surpassed only by silver, copper is a highly conductive metal. This means electricity can pass through it with greater ease, making it ideal for use in electrical wires. Companies can use other conductive metals to create electrical wires. Unless they use silver, though, the high conductivity properties of copper allow for a greater distance of electrical current travel. Companies can create longer, better performing electrical wires using copper instead of most other conductive metals.

<h2>Inexpensive </h2>

Copper is also relatively inexpensive when compared to other metals. Gold, for example, is an excellent conductor of electricity, but it costs several times more than copper. If companies used gold to manufacture electrical wires, they’d essentially waste money, as copper is more conductive and costs less than its goal counterpart. This alone is reason enough to make copper the de-facto standard for electrical wires.

<h2>High Ductility </h2>

Copper isn’t just conductive; it’s also ductile. In other words, you can bend and flex copper — to some degree — without it breaking or otherwise sustaining damage. Why is this important? Well, electrical wires must often travel through walls, floors, ceilings and other tight spaces. As a result, they’ll naturally bend and snake their way around the home or building in which they are used. The ductile properties of copper allow copper electrical wires to bend and flex. They’ll still transmit electricity, and they won’t lose any power strength from shape deformity.

<h2>Thermal Resistant </h2>

A benefit of copper electrical wires that’s often overlooked is its thermal-resistant properties. According to ESFI, electrical fires are responsible for more than 51,000 residential house fires in the United States each year — and that’s not accounting for commercial/business fires. Copper electrical wires are safer to use than wires made of most other conductive metals because they are resistant to heat.

<h2>As you can see, copper is the preferred metal for electrical wires for several reasons. It has high electrical conductive; it’s inexpensive; it’s ductile; and it’s thermal resistant. This makes is the universally accepted standard for the manufacturing of electrical wires.</h2>

<h2 />
3 0
2 years ago
Neutrons have neither charge nor mass.<br> TRUE<br> FALSE
iren2701 [21]

Answer:

FALSE

nuetrons do indeed have no charge, however they are nearly 2000 more times massive than electrons.

7 0
3 years ago
Consider the following isotopic symbol: 137Ba2+
aliya0001 [1]

Answer:

a) 56 protons

b) 54 electrons

c) 81 neutrons

d) The sum of protons and neutrons is shown. The number of protons is always the same. So we can calculate the number of neutrons ( and also the isotopes)

e)137Ba (with 56 protons and 81 neutrons)

f) atomic mass is 136.9 u ; the mass number is the sum of protons and neutrons and is 137

Explanation:

Step 1: Data given

137 Ba2+ is an isotope of barium. The atomic number of barium( and its isotopes) is 56. This shows the number of protons.

For a neutral atom, the number of protons is equal to the number of electrons.

The different isotopes of an element have the same number of protons but a different number of neutrons.

137Ba2+ has 56 protons (this is the same as the atomic number)

137Ba2+ has 54 electrons ( since it's Ba2+, this means it has 2 electrons less than protons, that's why it's charged +2)

137Ba2+ has 81 neutrons ( 137 - 56 = 81)

In the symbol, the atomic number is not shown. The sum of the protons and neutrons is shown. (Since the number of protons is the same for every isotope, we can calculate the number of neutrons that way. By knowing the neutrons, we also know the isotope.

This isotope is 137Ba

Atomic mass is also known as atomic weight. The atomic mass is the weighted average mass of an atom of an element based on the relative natural abundance of that element's isotopes.

The atomic mass of 137Ba2+ is 136.9 u

The mass number is a count of the total number of protons and neutrons in an atom's nucleus.

The mass number of 137Ba2+ is 137

3 0
3 years ago
According to the law of conservation of energy, the energy released by the system must be transferred to and absorbed by the sur
Andrew [12]
True! 
 Energy released by system is absorbed by surroundings.
5 0
3 years ago
One of the products of a fermentation reaction is
Alex73 [517]
There are two types of fermentation aerobic and anaerobic. Aerobic are those that need oxygen to ferment while anaerobic are those who do not need oxygen. Products of fermentation are usually water, ethanol, lactic acid and carbon dioxide. Other products are acetone and butyric acid.
5 0
3 years ago
Other questions:
  • What does tectonic activity refer to
    14·1 answer
  • The end point in a titration of a 58mL sample of aqueous HCl was reached by the addition of 25mL of 0.83MNaOH titrant. The react
    15·1 answer
  • What product is formed when a group 1 metal reacts with a halogen?
    13·1 answer
  • The density of lead is 11.3
    9·2 answers
  • What properties of a substance determine how that substance will react when combined with other substances?
    8·2 answers
  • A
    9·1 answer
  • What is the molality of a solution that has 30mg of K3PO4 dissolved in 40mL of water? (The density of water is 1.00 g/mL)
    7·1 answer
  • MAJOR, PLEASE HELP, BRAINEST IF CORRECT
    5·1 answer
  • Plss answer!!! I need help fast
    14·2 answers
  • What is the [Na2SO4] (MM = 142.04 g/mol) in ppt if 100.00 mL of a
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!