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
TiliK225 [7]
3 years ago
10

Hello, I would really appreciate it if you guys can answer the question below, it is for marks and I do not know the answer for

this one so please help I only have 19 min left.

Chemistry
1 answer:
Taya2010 [7]3 years ago
3 0

Answer:

Two human needs are food and water. We need food to survive so we dont starve to death. And water is most important because without water after around five days, you die. Heat technology could be fire. We use fire to distill salt water. Distilling salt water boils the bacteria and so it would be safe to drink. We also use fire to cook the food we have gotten or hunted so we dont get infected with deadly bacteria and viruses.

Explanation:

Hope this helps. Have a nice day!

You might be interested in
There are two naturally occurring isotopes of copper. 63cu has a mass of 62.9296 amu. 65cu has a mass of 64.9278 amu. determine
SSSSS [86.1K]
1) You need to use the atomic mass of copper.


You can find it in a periodic table. It is 63.546 amu.


2) The atomic mass is the weigthed mass of the different isotopes.


This is, the atomic mass of one element is the atomic mass of each isotope times its corresponding abundance:


=> atomic mass of the element = abundance isotope 1 * atomic mass isotope 1 + abundance isotope 2 *  atomic mass isotope 2 + ....+abundance isotope n * atomic mass isotope n.


3) The statement tells there are two isotopes so the abundance of one is x and the abundance of the other is 1 - x


=> 63.546 amu = x * 62.9296 amu + (1-x)*64.9278


=> 63.546 = 62.9296x + 64.9278 - 64.9278x


=> 64.9278x - 62.9296 = 64.9278 - 63.546


=> 1.9982x = 1.3818


=> x = 1.3818 / 1.9982 = 0.6915 = 69.15%


=> 1 - x = 1 - 0.6915 = 0.3085 = 30.85%


Answer:


Cu-63 69.15%;


Cu-65 : 30.85%
3 0
3 years ago
Plzz help in this i have an exam today​
Zielflug [23.3K]

Answer:

a and c are reduction

b and d are oxidation

8 0
3 years ago
How do you determine the group and period of an element based on its electron configuration?
il63 [147K]

Answer:

If you are given with the atomic number of an element you can find it's period number and group number. The period number is related to the number of electron occupied shells in the element and the period number is linked to its valence electrons.

Explanation:

hope it helps luv <3

4 0
3 years ago
19) What is the molarity of a KOH solution if 200 ml of the solution contains 0.6 moles KOH?
zloy xaker [14]

Answer: 3M

Explanation: Molarity : It is defined as the number of moles of solute present in one liter of solution.

Formula used :

Molarity=\frac{n\times 1000}{V_s}

where,

n = moles of solute KOH = 0.6 moles

V_s = volume of solution in ml= 200 ml

Now put all the given values in the formula of molarity, we get

Molarity=\frac{0.6moles\times 1000}{200ml}=3mole/L

Therefore, the molarity of solution will be 3M.

8 0
3 years ago
Read 2 more answers
Which of the following chemical reactions is an oxidation-reduction reaction? Fe2O3 + 3CO yields 2Fe + 3CO2 MgSO4 + 2KIyields K2
Elodia [21]
I hope I am right on this, but the answer is
Fe₂O₃ + 3CO --> 2Fe + 3CO₃
5 0
3 years ago
Read 2 more answers
Other questions:
  • Explain how the scientific method helps scientists.
    9·1 answer
  • How is group work similar to interacting with people in your family?
    12·1 answer
  • Suppose that the pressure of 0.66 L of gas is 424.9 mm Hg when the temperature is 261.2 K. At what temperature is the volume 7.6
    5·2 answers
  • What is the difference between the 3p sublevel and the 4p sublevel?<br><br> On the periodic table
    6·1 answer
  • Witch two conditions can limit the usefulness of the kinetic molecular theory in describing gas behavior?
    11·2 answers
  • What is the electron structure of sodium
    9·2 answers
  • How does a tiny seed turn into a tree overtime?
    9·1 answer
  • Can anyone help me with this question?? <br><br> No links please!
    7·1 answer
  • Is phosphorus a pure substance or mixture
    14·2 answers
  • Why is it important to determine the heat capacity of the calorimeter?.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!