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
sdas [7]
3 years ago
14

The half life of a radioactive element is 2 million years. a mass of rock originally contained 200g of this element. how many gr

ams of the element are left after 4 million years?
Chemistry
1 answer:
julia-pushkina [17]3 years ago
8 0
Every 2 million years the amount is halved
0 million = 200g
2 million = 200g/2 = 100g
4 million = 100g/2 = 50g
You might be interested in
Q- Which two positions show the location of the moon in its gibbous phases as seen from Earth?
Phoenix [80]

Answer: 6 & 8

Explanation:

I got it correct on my test hope this helped

4 0
3 years ago
How does the use of synthetic oil impact the natural resource from which they are derived?
omeli [17]
Its destructing the nature
5 0
3 years ago
What is the pH of a solution made by mixing 30.00 mL 0.10 M HCl with 40.00 mL of 0.10 M KOH? Assume that the volumes of the solu
nirvana33 [79]

Answer:

pH = 12.15

Explanation:

To determine the pH of the HCl and KOH mixture, we need to know that the reaction is  a neutralization type.

HCl  +  KOH  →  H₂O  +  KCl

We need to determine the moles of each compound

M = mmol / V (mL) → 30 mL . 0.10 M = 3 mmoles of HCl

M = mmol / V (mL) → 40 mL . 0.10 M = 4 mmoles of KOH

The base is in excess, so the HCl will completely react and we would produce the same mmoles of KCl

HCl  +  KOH  →  H₂O  +  KCl

3 m       4 m                       -

             1 m                      3 m

As the KCl is a neutral salt, it does not have any effect on the pH, so the pH will be affected, by the strong base.

1 mmol of KOH has 1 mmol of OH⁻, so the [OH⁻] will be 1 mmol / Tot volume

[OH⁻] 1 mmol / 70 mL = 0.014285 M

- log [OH⁻] = 1.85 → pH = 14 - pOH → 14 - 1.85 = 12.15

3 0
3 years ago
Which has the highest electronegativity value?
AnnZ [28]
Which has the highest electronegativity value?
A
hydrogen

B
calcium

C
helium

D
fluorine d because fluorine has a higher group number

8 0
3 years ago
When HBr combines with water, it produces H3O+ and Br- ions. This shows that HBr is a base. true false
ELEN [110]
HBr is a strong acid

False
6 0
4 years ago
Read 2 more answers
Other questions:
  • If the temperature of a piece of steel decreases, what happens to its density? a. The density decreases. b. The density increase
    5·2 answers
  • What amount of heat energy is required to raise the temperature of 152 g of water from 24 °C to 74 °C.
    5·1 answer
  • A chemist prepares a solution of barium acetate by measuring out of barium acetate into a volumetric flask and filling the flask
    14·1 answer
  • Using any data you can find in the ALEKS Data resource, calculate the equilibrium constant K at 30.0 °C for the following reacti
    7·1 answer
  • about how long does it take for the reaction to reach equilibrium in this concentration versus time graph?
    5·2 answers
  • Titanium metal requires a photon with a minimum energy of 6.94×10⁻¹⁹J to emit electrons. What is the wavelength of this light? E
    6·1 answer
  • 2. If 45.4 grams of H20 are formed during the reaction, how many moles of Oz reacted?
    13·1 answer
  • A rock _____ can get polished from water running over it?
    10·2 answers
  • El dicromatico de potacio conduce electricidad y porque?
    5·1 answer
  • Write equations for the following: (b) an addition reactionbetween cyclohexene and Cl₂;
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!