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
AleksAgata [21]
2 years ago
13

Which evidence is an indication that a chemical reaction has occurred?

Chemistry
1 answer:
Luden [163]2 years ago
8 0

Answer:

  • Some signs of a chemical change are a change in color and the formation of bubbles. The five conditions of chemical change: color change, formation of a precipitate, formation of a gas, odor change, temperature change.

You might be interested in
3.95 g of sugar (C6H12O6) is dissolved in water to make 158 mL of solution. Find the molarity.
12345 [234]

Answer:

[C₆H₁₂O₆] = 0.139 M

Explanation:

Molarity si defined as a sort of concentration. It indicates the moles of solute that are contained in 1 L of solution.

We can also say, that molarity are the mmoles of solute contained in 1 mL of solution.

For this case, the solute is sugar (glucose). Let's determine M (mmol/mL)

(3.95 g . 1mol / 180g) . (1000 mmol / 1mol) / 158 mL

We determine moles, we convert them to mmoles, we divide by mL

M = 0.139 M

Moles = 3.95 g . 1mol / 180g → 0.0219 mol

We convert mL to L → 158 mL . 1L/1000mL = 0.158L

M = 0.0219 mol / 0.158L = 0.139 M

8 0
3 years ago
20 points! < is what I chose. How did I do?
Zigmanuir [339]

Greenhouse gases released from the burning of fossil fuels are responsible for global warming.

<h3>What is the atmosphere?</h3>

The atmosphere is the region of region of the planet above its surface area where gases envelop the planet.

Based on the effect of greenhouse gases on global warming;

  • Planet A has a higher surface temperature due to the higher amount of carbon dioxide in the atmosphere since carbon dioxide is a greenhouse gas.
  • Methane is the main constituent of natural gas. Humans increase the contribute to increase in methane gas by raising cattle,
  • Pollutants come from both natural sources and human activities.
  • Sulfur Dioxide is produced by the combustion of fuels in automobiles. Once in the atmosphere, it combine with water to form acid precipitation.
  • Nitrogen and oxygen do not contribute to the greenhouse effect because they are  made up of 2 atom molecules that are bound tightly so they CANNOT vibrate to absorb energy.
  • Greenhouse gases contribute to global warming by absorbing infrared energy that reflects off Earth's surface and reemitting the energy in all directions. This keeps the infrared energy close to the Earth's surface.
  • Most of the greenhouse gases produced come from burning fossil fuels in factories, ships, cars, trains.

Therefore, pollutants such as greenhouse gases are responsible for global warming.

Learn more about greenhouse gases at: brainly.com/question/12684997

#SPJ1

8 0
2 years ago
Help <br> whoever answers all gets marked brainliest
Lelechka [254]

#1

  • See H and C have shared their electrons so it's Covalent bonding

#2

Yes here we can see the dots and crosses clearly.

  • Dot and crosses digram

#3

It's Methane or CH_4

  • 4 single bonds

#4

There is no double bond

6 0
3 years ago
Read 2 more answers
Which of the following is the best definition of convection?
lara [203]
<span>a) movement of heat through space </span>
7 0
3 years ago
Read 2 more answers
How many particles are present in 12.47 grams of NaCl
liq [111]

Answer:

1.26*10²³ particles are present in 12.47 grams of NaCl

Explanation:

Avogadro's Number or Avogadro's Constant is called the number of particles that make up a substance (usually atoms or molecules) and that can be found in the amount of one mole of said substance. Its value is 6.023 * 10²³ particles per mole. The Avogadro number applies to any substance.

So, first of all you must know the amount of moles that represent 12.47 grams of NaCl. For that it is necessary to know the molar mass.

You know:

  • Na: 23 g/mole
  • Cl: 35.45 g/mole

So the molar mass of NaCl is: 23 g/mole + 35.45 g/mole= 58.45 g/mole

Now you apply a rule of three as follows: if 58.45 grams are present in 1 mole of NaCl, 12.47 grams in how many moles will they be?

moles=\frac{12.47 grams*1 mole}{58.45 grams}

moles= 0.21

You apply a rule of three again, knowing Avogadro's number: if in 1 mole of NaCl there are 6,023 * 10²³ particles, in 0.21 moles how many particles are there?

number of particles=\frac{0.21 moles*6.023*10^{23} }{1 mole}

number of particles= 1.26*10²³

<u><em>1.26*10²³ particles are present in 12.47 grams of NaCl</em></u>

<u><em></em></u>

5 0
3 years ago
Other questions:
  • Which of the following is the basis Rutherford's planetary model
    9·2 answers
  • how do modern tools such as Doppler radar satellite weather balloons and computers help meteorologist understand weather
    11·1 answer
  • I will give u 14 points if u get this right​
    9·1 answer
  • WHAT IS THE DEFINITION FOR ISOTOPES, WHAT ARE EXAMPLES OF ISOTOPES, WHAT ARE NON EXAMPLES OF ISOTOPES AND WHAT ARE EXAMPLES OF I
    10·2 answers
  • For potassium metal, the work function ф(the minimum energy needed to eject an electron from the metal surface) is 3.68 x 1019 J
    13·1 answer
  • If a man has a mass of 83 kilograms on Earth, what will the force of gravity on his body be on the moon? A. 135.6 N B. 318.5 N C
    9·2 answers
  • The Henry's Law constant of methyl bromide, CH3Br, is k = 0.159 mol/(L ⋅ atm) at 25°C. What is the solubility of methyl bromide
    9·1 answer
  • Simplify (4f+13g)(2w)
    8·2 answers
  • can you guys help me out??? How do different plant structures increase the chances for successful reproduction? Use evidence to
    12·1 answer
  • What of the following is the BEST statement about dependent and independent variables?
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!