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
melamori03 [73]
3 years ago
7

Hydrogen is unique among the elements because __________. 1. It has only one valence electron. 2. It is the only element that ca

n emit an atomic spectrum. 3. Its electron is not at all shielded from its nucleus. 4. It is the lightest element. 5. It is the only element to exist at room temperature as a diatomic gas.
Chemistry
1 answer:
Talja [164]3 years ago
6 0

Answer:

3,4

Explanation:

Hydrogen has no other electron hence there is no screening of the valence electron by inner electrons. It is the lightest known element with a relative molecular mass of 2. Screening effect refers to the fact that inner or core electrons prevent the outermost electron from feeling the attractive force of the nucleus.

You might be interested in
PLEASE HELP DUE TODAY
11111nata11111 [884]

Formula mass, molar mass and Avagadro's number.

Explanation:

number of atoms in a compound can be calculated by knowing the molar mass of the compound or element, the result will be multiplied by avagadro's number (6.022*10^23)

1 mole of a substance is equal to Avagadro number of atoms.

If the number of moles is known of a compound or element its molar mass can be calculated as:

n= Weight of the compound/element given/ molecular weight of the same.

  formula mass is the mass of compound ie chemical compound formed with different molecules. its mass is calculated by adding the molar masses of all the elements taking part in its assembly.

5 0
3 years ago
Which equation best represents the net ionic equation for the reaction that occurs when aqueous solutions of potassium phosphate
laiz [17]

Answer:

2PO₄³⁻ + 3Fe²⁺ → Fe₃(PO₄)₂(s)

Explanation:

In a net ionic equation you list <em>only the ions that are participating in the reaction. </em>

When potassium phosphate, K₃PO₄, reacts with iron (II) nitrate, Fe(NO₃)₂ producing iron (II) phosphate, Fe₃(PO₄)₂ that is an insoluble salt. The reaction is:

2K₃PO₄ + 3 Fe(NO₃)₂ → Fe₃(PO₄)₂(s) + 6NO₃⁻ + 6K⁺

The ionic equation is:

6K⁺ + 2PO₄³⁻ + 3Fe²⁺ + 6NO₃⁻→ Fe₃(PO₄)₂(s) + 6NO₃⁻ + 6K⁺

Subtracting the K⁺ and NO₃⁻ ions that are not participating in the reaction, the net ionic equation is:

<h3>2PO₄³⁻ + 3Fe²⁺ → Fe₃(PO₄)₂(s)</h3>

8 0
3 years ago
DO NOT ANSWER IF YOU DO NOT KNOW WHAT TO DO
Mice21 [21]

Answer:

im gunna save my answer so no one can take it:)

Explanation:

I tried my best

4 0
3 years ago
Read 2 more answers
1.Which statement best describes an oxidation-reduction reaction?(1 point)
Nataly_w [17]

Answer:

D

Explanation:

7 0
3 years ago
When taking a measurement of temperature which tool should be used
Tcecarenko [31]

Answer:

A thermometer is the appropiate tool to use.

Explanation:

4 0
3 years ago
Read 2 more answers
Other questions:
  • What charge does 3protons 3neutrons 2electrons
    6·1 answer
  • Jailah needs a replacement for lithium for a science experiment. She tries silicon, but it does not work. Using what you know ab
    9·1 answer
  • The total number of electrons in a neutral atom of every element is always equal to the atom's
    13·1 answer
  • PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE HELP PLEASE H
    7·1 answer
  • How much energy (in J) is lost when a sample of iron with a mass of 28.3 g cools from 66.0 degrees celsius to 24.0 degrees celsi
    14·1 answer
  • Chlorine and Hydrogen
    12·1 answer
  • Please help me asap thank you
    9·1 answer
  • How many water molecules self ionize in one liter of water
    14·1 answer
  • Pls help if you only know the correct answer! Thanks! :)
    11·1 answer
  • A buffer is prepared by adding 300. 0 ml of 2. 0 mnaoh to 500. 0 ml of 2. 0 mch3cooh. what is the ph of this buffer? ka= 1. 8 10
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!