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Solnce55 [7]
3 years ago
13

Which of the following measurements is expressed to three significant figures? 7.30 × 10–7 km 0.007 m 7077 mg 0.070 mm

Chemistry
1 answer:
Sonbull [250]3 years ago
4 0

7.30 x 10^-7 km. the others have 4 significant figures.

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What is bias in an experiment?
N76 [4]

○ c. ○

◘

because a Research bias, also called experimenter bias, is a process where the scientists performing the research influence the results, in order to portray a certain outcome.

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hope that helped ♥

3 0
3 years ago
list 10 chemical reactions that have benefited your life today. Include the reasons you think each was indeed a chemical reactio
Dennis_Churaev [7]

1) The overall balanced photosynthesis reaction:  

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.

Plants convert solar energy into the chemical energy of sugars (food).

2) Chemical reaction of cellular respiration:  

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O.

Organic carbon (glucose) is transformed into inorganic carbon (carbon dioxide) that goes into atmosphere.

3) Gasoline combustion:

C₈H₁₈ + 25/2O₂ → 8CO₂ + 9H₂O.

Gasoline is a mixture of many different hydrocarbons: alkanes (paraffins), cycloalkanes and alkenes (olefins).

Gasoline is being burn.

4) Balanced chemical reaction of forming rust: 4Fe + 3O₂ → 2Fe₂O₃.

Forming rust usually last for few months and iron changing in another substance with different properties.

5) An electrochemical cell (voltaic or galvanic cell) is generating electrical energy from chemical reactions.  

In galvanic cell, specie (for example zinc and zinc cations) from one half-cell, lose electrons (oxidation) and species from the other half-cell (for example copper and copper cations) gain electrons (reduction).  

Oxidation on the zinc anode: Zn(s) → Zn²⁺(aq) + 2e⁻.

Reduction on the copper cathode: Cu²⁺(aq) + 2e⁻ → Cu(s).

Copper is forming from the solution, that is chemical change.

6) Balanced chemical reaction: CaO + H₂O → Ca(OH)₂.

Making limewater  (diluted solution of calcium hydroxide).

7) Neutralization is reaction in which an acid and a base react quantitatively with each other. In this reaction, there are no acids and bases, only salts.

Balanced chemical reaction of vinegar and antacid:

2CH₃COOH(aq) + Mg(OH)₂(aq) → (CH₃COO)₂Mg(s) + 2H₂O(l).

Precipation is formed.

8) Balanced chemical reaction of magnesium and hydrochloric acid:

MgO + 2HCl → MgCl₂ + H₂O(g).

Acid dissolves metal oxides.

9) Chemical reaction of silver in air:

4Ag + 2H₂S + O₂ → 2Ag₂S (tarnish) + 2H₂O.

Silver change color in the air.

10) Forming of patina: 2CuO + CO₂ + H₂O → Cu₂CO₃(OH)₂.

Brass (copper) change color to green.

4 0
3 years ago
Enter a balanced equation for the reaction between solid nickel(II)(II) oxide and carbon monoxide gas that produces solid nickel
velikii [3]

Answer: A balanced equation for the given reaction is NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g).

Explanation:

The reaction equation will be as follows.

NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)

Number of atoms on the reactant side is as follows.

  • O = 2
  • C = 1

Number of atoms on the product side is as follows.

  • Ni = 1
  • O = 2
  • C = 1

Since number of atoms on both the reactant and product sides are equal. Hence, the reaction equation is balanced.

Thus, we can conclude that a balanced equation for the given reaction is NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g).

7 0
3 years ago
If moving objects have kinetic energy, do moving atoms kinetic energy?
podryga [215]

Answer:

yes, if they were in rest they would have potential energy

Explanation:

7 0
2 years ago
When an atom undergoes beta decay, wich of the following is true?
tigry1 [53]
<span> The atomic number increases by one and the element becomes a different element. </span>
3 0
3 years ago
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