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
Anvisha [2.4K]
3 years ago
12

Which radioisotope is naturally occurring?

Chemistry
1 answer:
Lena [83]3 years ago
5 0

Answer:

I think the answer is 13H

Explanation:

The best known example of a naturally-occurring radioisotope is uranium. All but 0.7 per cent of naturally-occurring uranium is uranium-238; the rest is the less stable, or more radioactive, uranium-235, which has three fewer neutrons in its nucleus.

You might be interested in
(chem) which is more concentrated: 45.0 grams of HCOOH dissolved in 189 mL of water or 1.5 moles of CH↓2COOH dissolved in twice
Liula [17]

Answer:

CH3COOH would be more concentrated

Explanation:

The higher the concentration value, the more concentrated it is.

The relationship between concentration, moles and volume is given by the equation;

Concentration = No of moles / Volume

5.0 grams of HCOOH dissolved in 189 mL of water

Number of moles = Mass / Molar mass = 5 / 46.03 = 0.1086 mol

Concentration = 0.1086 / 0.189 = 0.5746 mol/L

1.5 moles of CH3COOH dissolved in twice as much water

Volume = 2 * 189 = 378 ml = 0.378 L

Concentration = 1.5 / 0.378 = 3.9683 mol/L

Comparing both concentration values;

CH3COOH would be more concentrated

6 0
2 years ago
What is the density of a block marble that occupies 255 cm^3 and has a mass of 1000g
RUDIKE [14]

Answer:

<h2>3.92 g/cm³</h2>

Explanation:

The density of a substance can be found by using the formula

density =  \frac{mass}{volume} \\

From the question we have

density =  \frac{1000}{255}  \\  = 3.921568...

We have the final answer as

<h3>3.92 g/cm³</h3>

Hope this helps you

4 0
3 years ago
What volume, in milliliters, of a 0.997 M KOH solution is needed to neutralize 30.0 mL of 0.0400 M HCl?
deff fn [24]

Answer:

1.2 mL

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated:

HCl + KOH —> KCl + H₂O

From the balanced equation,

Mole ratio of the acid, HCl (nₐ) = 1

Mole ratio of base, KOH (n₆) = 1

Finally, we shall determine the volume of the base, KOH needed to neutralize the acid, HCl as follow:

Molarity of base, KOH (M₆) = 0.997 M

Volume of acid, HCl (Vₐ) = 30 mL

Molarity of acid, HCl (Mₐ) = 0.0400 M

Volume of base, KOH (V₆) =?

MₐVₐ / M₆V₆ = nₐ/n₆

0.04 × 30 / 0.997 × V₆ = 1/1

1.2 / 0.997 × V₆ = 1

Cross multiply

0.997 × V₆ = 1.2

Divide both side by 0.997

V₆ = 1.2 / 0.997

V₆ = 1.2 mL

Thus, the volume of the base, KOH needed to neutralize the acid is 1.2 mL.

7 0
3 years ago
A nitrogen atom has five valence electrons. The Lewis structure shows how a nitrogen atom bonds with three hydrogen atoms to for
nordsb [41]
It has too be 6 or 4

3 0
2 years ago
Which description is true of 0.02 M Ca(OH)2 if Ca(OH)2 completely dissociates in water? A. It’s a dilute strong acid. B. It’s a
Sphinxa [80]

Answer: B. It’s a dilute strong base.


Explanation:


1) Definition of acids and bases: as per Bronsted-Lowry model, an acid is a substance that donates hydrogen ions and a base is a substance that accepts hydrogen ions.

Ca(OH)₂ does not have hydrogen ions to donate, but it can accept hydrogen ions to form H₂O according to this equation: H⁺ + OH⁻ → H₂O.

Hence,  Ca(OH)₂ is a base.


2) Definition of strong base: a strong base is a base that dissociates completely into metallic and hydroxide ions in aqueous solutions, while a weak base dissociates partially.


Hence, Ca(OH)₂ is a strong base.


3) Definition of dilute: it refers to a solution meaning that the substance is not pure and the concentration is low. Since, the solution the Ca(OH)₂ is 0.02 M means that it is dilute.


Therefore, we have found that the description of 0.02 M Ca(OH)₂ is that is is a dilute strong base (option B).


5 0
3 years ago
Other questions:
  • What is the pH of a solution with a concentration of 4.7 × 10-4 molar H3O+?
    11·1 answer
  • What geometry does VSEPR predict for the central atom in NCl3
    14·1 answer
  • What is the ph of an aqueous solution with the hydronium ion concentration?
    14·1 answer
  • Examples of quantitative of quantitative data
    6·2 answers
  • Quickly Please!!!!!!
    6·2 answers
  • The table shows the average distance between the molecules of a substance in the solid, liquid, and gaseous states.
    10·1 answer
  • PLEASE HELP!!!!! And thanks in advance
    14·2 answers
  • Which of the following conclusions is accurate?
    8·2 answers
  • What net force must act on the book to make it accelerate to the left at a rate
    11·1 answer
  • A gas cylinder contains exactly 1 mole of oxygen gas (O2). How many molecules of oxygen are in the cylinder?.
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!