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
s2008m [1.1K]
4 years ago
14

BRAINLIESTTT ASAP!!! PLEASE HELP ME :)

Chemistry
1 answer:
Alex_Xolod [135]4 years ago
5 0

It is the 3rd option. Theories must be substantiated by a large amount of evidence and previous research

You might be interested in
Why is urbanization contributing to pollution? People in urban areas strip the soil of nutrients and make it difficult to grow c
slavikrds [6]

We have to know how urbanization causes pollution.

The reason is: People in urban areas consume more energy, food, and water.

Urbanisation is one of the major problem towards pollution. The smoke from automobiles, factories and power generators make air unhealthy. Also chemical spills and other toxic gases contaminate in air.

The mixing of toxins in the soil is polluting soil which disturbs eco-system.

The high density population in urban area consume more energy , food and water which causes pollution.

7 0
3 years ago
Read 2 more answers
Which of the following is the correct formula for Ca2+ reacting with NO2??
mariarad [96]

Answer:

B. Ca(NO2)2

Explanation:

Ions (charged atoms) combine with one another to form stable ionic compounds. In this case, calicium ion (Ca2+) is said to react with NO2, which has a charge of -1 i.e. +1-1(2) = 1-2 = -1.

This means that calcium has a charge of +2 while nitrite ion has charge of -1, hence, when they combine, they exchange their charges, which become their subscript as follows:

Ca2+ + NO2- → Ca(NO2)2

Ca(NO2)2 is a stable ionic compound called calcium nitrite. Notice that it takes two atoms of NO2- to react with one atom of Ca2+.

5 0
3 years ago
Water boiling and turning into steam<br><br> is a chemical or physical change?
olga2289 [7]

Answer:

physical change

Explanation:

8 0
4 years ago
Read 2 more answers
a helium balloon has a volume of 2.95 liters at 25 c. the volume of the ballon decreased to 2.25 l after it is placed outside on
OleMash [197]

Answer:

The outside temperature is -45.8°C

Explanation:

When a gas keeps on constant its moles and its pressure, we can assume that volume will be increased or decreased as the T° (absolute T° in K).

V1 / T1 = V2 / T2

2.95L/298K = 2.25L / T2

(2.95L/298K ) . T2 = 2.25L

T2 = 2.25L . 298K / 2.95L

T2 = 227.2K

T°K - 273 = T°C

227.2K - 273 = -45.8°C

3 0
4 years ago
How to find nuetrons
ValentinkaMS [17]
To find the number of neutrons, subtract the number of protons from the mass number. number of neutrons=40−19=21.
3 0
2 years ago
Other questions:
  • consideras util conocer las propiedades extensivas e intensivas de los insumos utilizados para la elaboración de producto ¿por q
    14·1 answer
  • How much mass would a mole of nitrogen molecules contain? Recall that nitrogen is diatomic. g/mol
    5·1 answer
  • Based on your knowledge of how the greenhouse effect works, why does the level of carbon dioxide affect the global temperature?
    14·2 answers
  • An electron is traveling at 1.500 × 105 m/s. What is its speed in light years per century? (useful conversion factors: 1 light-y
    9·1 answer
  • Deep sea divers use a mixture of helium and oxygen to breathe. Assume that a diver is going to a depth of 150 feet where the tot
    5·1 answer
  • Which of the following is correctly abbreviated SI unit describing the mass of an object?
    13·2 answers
  • All living organisms are made out of cells. Select three cell parts that all cells contain.
    13·1 answer
  • Pleaseeeeeeeee
    7·1 answer
  • How does the structure of compounds determine the properties of the compounds?
    13·1 answer
  • HELP ME OUT PLS!!!!!
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!