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
Vesna [10]
3 years ago
10

If you have 100 grams of a radioactive isotope with a half life of 10 years how much of the isotope will you have left after 20

years
Chemistry
1 answer:
Cerrena [4.2K]3 years ago
3 0

Hey there!

A half-life means after a certain amount of time, half of that substance will be gone/changed after that time.

There are two half lives in 20 years because 20 ÷ 10 = 2.

So, we divide the 100g sample in half 2 times.

100 ÷ 2 = 50

50 ÷ 2 = 25

There will be 25g of the radioactive sample remaining after two half lives.

Hope this helps!

You might be interested in
All atoms of an element have the same number of ________. electrons neutrons protons protons plus neutrons
Cloud [144]

Answer:

protons

Explanation:

An element, by definition, always has the same number of protons.  Sodium, element 11, has 11 protons.  Anything with 11 protons is a sodium atom, regardless of the number of neutrons, electrons, or politicians.  

6 0
2 years ago
What would be the electron configuration of a sulfur ion S−2?
MAVERICK [17]

It's either B or C heh

4 0
3 years ago
Read 2 more answers
Calculate the number of chlorine atoms that are present in 66.05 g of dichloromethane, ch2cl2. when you have the number, take it
Whitepunk [10]
From the periodic table:
mass of carbon = 12 grams
mass of hydrogen = 1 gram
mass of chlorine = 35.5 grams
Therefore,
molar mass of CH2Cl2 = 12 + 2(1) + 2(35.5) = 85 grams

number of moles = mass / molar mass
number of moles of CH2Cl2 = 66.05 / 85 = 0.777 moles

One mole of CH2Cl2 contains two moles of Cl and each chlorine mole has Avogadro's number of atoms in it.
Therefore,
number of chlorine atoms in 0.777 moles of CH2Cl2 can be calculated as follows:
number of atoms = 0.777 * 2 * 6.022 * 10^23 = 9.358 * 10^23 atoms

Now, we will take log base 10 for this number:
log (9.358 * 10^23) = 23.97119
5 0
3 years ago
How many electrons in an atom can share the quantum numbers n = 4 and l = 3?
o-na [289]

Answer:

\boxed{\text{14}}

Explanation:

If l = 3, the electrons are in an f subshell.

The number of orbitals with a quantum number l is 2l + 1, so there

are 2×3 + 1 = 7 f orbitals.

Each orbital can hold two electrons, so the f subshell can hold 14 electrons.

\boxed{\textbf{14 electrons}} \text{ can share the quantum numbers n = 4 and l = 3.}

3 0
3 years ago
A phase is a part of a system with what type of composition?
TiliK225 [7]

Answer:

<u>uniform composition.</u>

Explanation:

A phase is a part of a system with uniform composition.

  • In physics and chemistry , a phase in a physically distinctive form of matter , such as solid , liquid , gas or plasma.
  • A phase matter is characterised by having relatively uniform chemical and physical properities . Phases are different from states of matter.
  • The states of matter (e.g ., solid , liquid , gas ) are phases but matter can exist in different phases and yet be in the same type of matter. For example , liquid mixtures can exist in multiple phases such as oily and aqueous phase.
  • some different types of phases are : solid, liquid,gas , plasma etc.
  • The term phase can also sometime mean describe equilibrium in phase diagram
6 0
3 years ago
Other questions:
  • The correct mathematical expression for finding the molar solubility (s) of calcium phosphate is
    13·1 answer
  • According to newtons third law forces always occur in equal but____ pairs?
    13·1 answer
  • How many electrons, protons, and neutrons are contained in the 17o?
    12·1 answer
  • An atom of oxygen (atomic number 8) with an atomic mass of 16 would have how many neutrons?
    10·1 answer
  • Competition occurs when two or more organisms within an ecosystem seek the same resource. Which of the following is an example o
    10·2 answers
  • The pressure caused by a sample of gas is 2.25 atm. 1 atm is
    9·1 answer
  • What are the three major branches of natural science?
    5·2 answers
  • Answer the following problem-
    5·1 answer
  • What is NOT a condition needed for a hurricane to form?
    7·1 answer
  • Please help Why can we listen to radio or watch TV indoors?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!