A food item that is left out of the refrigerator turns brown and forms bubbles and gas. What are the signs that this is a chemical reaction?

Check all that apply.

Heat is produced.
Heat is absorbed.
Bubbles appear.
A precipitate forms.
The color changes.

Answers

Answer 1
Bubbles appear and the color changes
Answer 2

Answer:

C & E

Explanation:


Related Questions

which type of experiment follows ethical standars?
A.Releasing contaminated waste into water system?
b. perfoming test on animals when the information can be obtained in other ways?
c. doing research on animals in which the animal experiences to fear or pain.
d. perfoming tests on people who cannot protect themselfs?

Answers

Answer:

A.Realesing contaminated waste into the water system

Explanation:

because if you you try it would really work

C is your answer to the question

What is the coefficient for titanium tetrachloride when the equation below is balanced?
TiCl4 + H2O TiO2 + HCl

a. 4
b. 1
c. 2
d. 3

Answers

Answer:

I believe that it is B. 1

Explanation: I could be wrong but I believe its 1

What else is produced during the replacement reaction of silver nitrate and potassium sulfate? 2AgNO3 + K2SO4 Ag2SO4 + ________

Answers

Answer:

c

Explanation:

Answer:

c

Explanation:

Please help, im really confused. ill mark brainliest

Answers

Answer:

Fossils of the same animals have been found on South America and on Africa.

Africa and South America look as if they could be fit together perfectly (they almost can!)

Explanation:

Basically, the idea is that South Africa and Africa were once the same landmass. The same animals lived in that landmass, but when they broke off, then the animals were on different continent, yet they came from the same place.

Which term is the rate at which work is done

Answers

Work is done by doing it

Answer:

1

Explanation:

An average human body has 84.0 g of chlorine (as chloride ions) in it. If the average mass of a human body is 70.0 kg, what is the concentration of chlorine in ppth?

Answers

Answer:

[tex]ppth=1.2ppth[/tex]

Explanation:

Hello!

In this case, since the parts per thousand of a solute in a solute is defined in terms of its grams per kilogram of solution (unlike parts per million which are mg/kg) we can mathematically represent it via:

[tex]ppth=\frac{grams_{solute}}{kg{solution}}[/tex]

Now, since the whole human body acts as the solution and the chlorine in the form of ions as the solute, the required ppth turns out:

[tex]ppth=\frac{84.0g}{70.0kg}\\\\ppth=1.2ppth[/tex]

Best regards!

Which of the following is always altered when a substance undergoes a
chemical change?
a- state of matter of the substance
b- color of the substance
c- mass of the substance
d- arrangement of the atoms composing the substance

Answers

color of the substance

at what temp does h2o melt

Answers

Answer:

32 degrees fahrenheit

Explanation:

32 degrees Fahrenheit and 0 degrees Celsius

How many sp2 and sp3 are in caffeine?

Answers

Answer:

5.56×10²² molecules of AlPO4

Explanation:

i think thats is the correct answer if its wrong im really sorry

in a closed system as the temperature of a liquid increases the vapor pressure of the liquid

Answers

The vapor pressure of a liquid varies with its temperature, as the following graph shows for water. The line on the graph shows the boiling temperature for water. As the temperature of a liquid or solid increases its vapor pressure also increases. Conversely, vapor pressure decreases as the temperature decreases.

State the type of stability of Cl- ion.​

Answers

The common Cl– anion is clearly more stable than the highly charged Cl11– ion. Cl– has an outer octet of electrons (but not a full shell), and Cl11– has a full outer shell (but more than an octet). 18. The neutral atom is clearly more stable than the highly charged Cl11– ion.

Which root word of the binary ionic compound ends with -ide?

The metal
The positive ion
The non-metal
The group 1 element

Answers

The positive ion Yeah

Answer: the non metal

Explanation:

Organic materials are from ___________things.

A. Living
B. Dead

EASY POINTS

Answers

B trust me please ..........

Answer:

both

Explanation:

depends on what type because there is fecal material dead tissue decomposing soooo both

What best describes the reactants and products in a reaction at equilibrium?
more reactants form than products
they form at equal rates
more products form than reactants
they form equal amounts

Answers

Answer: they form at equal rates

Explanation:

By definition, at equilibrium, the rate of the forward reaction is equal to the rate of the reverse reaction.

An atom is defined as the smallest part of an element that...?

Answers

Answer:

takes part in a chemical reaction

Explanation:

An atom is defined as the smallest part of an element that takes part in a chemical reaction.

When chemicals react, they simply exchange their atoms and recombine to form compounds where the atoms inside of them have a stable configuration.

In a chemical reaction, atoms are not broken down to simpler forms. Chemical reactions do now break down atoms. By losing, sharing or gaining of electrons, atoms simply form compounds and molecules.

which evidence is an indication that a chemical reaction has occured

Answers

Answer:

color change

Explanation:

Answer:

There are three main indications when a chemical reaction occurs.

1. Energy change.

2. Color change.

3. Formation of new substance, which is the most suitable indication of a chemical change.

got the answer, so in other words, I'm good.

Answers

Answer:

Brainliest?

Explanation:

pls!!!!!

Hi, I could really use your help. The question is Which of the products would you anticipate being formed in the least molar quantity? That is, which of the products (1, 2, or 3) is the minor product? Explain your choice. HINT: Consider the intermediates formed.

Answers

Answer:

Number 1 will be in the lowest molar quantity b/c formation of 1st order products are more difficult to form than secondary (#2) or tertiary (#3) substitution products.  

Explanation:

In general, if a substitution occurs such that it is attached to a carbon that's attached to only one carbon, it is referred to as a primary carbon substitution. If a substitution occurs on a carbon that is attached to two (2) carbons, it is a secondary carbon substitution. Finally, if a substitution occurs such that it is attached to a carbon that's attached to three (3) carbons it is a tertiary substitution. Typically, primary substitution products follow an Sn2 type reaction pathway. Such requires the formation of only one intermediate that difficult to form as compared to 2° or 3° intermediates. Once formed, however, they will be very unstable and proceeds to product very quickly. Such produce very low product yield. The intermediates for 2° and 3° form more easily and are more stable in the reaction environments. An example is tertiary butyl halogens (e.g., t-butyl chloride) follow and Sn1 type reaction pathway forming a tertiary carbocation which then reacts with a nucleophile of choice and forms much higher yields than the 1° carbon substitution reactions. Suggest reviewing Sn2 and Sn1 substitution reactions.

The most useful property of metalloids is their
(A) Varying ability to conduct electric current.
(B) Softness and malleability.
(C) Tendency to be unreactive.
(D) Ability to be pulled out into long wires.

Answers

Answer:

An element is the simplest form of matter that cannot be split into simpler substances or built from simpler substances by any ordinary chemical or physical method. There are 110 elements known to us, out of which 92 are naturally occurring, while the rest have been prepared artificially. Elements are further classified into metals, non-metals, and metalloids.

Table 2.11.1: Characteristic properties of metallic and non-metallic elements:

Distinguishing luster (shine)

Non-lustrous, various colors

Nonmetals

Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gaseous, liquids or solids.

Physical Properties of nonmetals:

Physical State: Most of the non-metals exist in two of the three states of matter at room temperature: gases (oxygen) and solids (carbon).

Non-Malleable and Ductile: Non-metals are very brittle, and cannot be rolled into wires or pounded into sheets.

Conduction: They are poor conductors of heat and electricity.

Luster: These have no metallic luster and do not reflect light

Conductivity: Poor conductors of heat and electricity

Melting and Boiling Points: The melting points of non-metals are generally lower than metals

Seven non-metals exist under standard conditions as diatomic molecules:

H2(g)

N2(g)

O2(g)

F2(g)

Cl2(g)

Br2(l)

I2(l) (volatile liquid - evaporates readily)

Chemical Properties of Nonmetals

Non-metals have a tendency to gain or share electrons with other atoms. They are electronegative in character.

Nonmetals, when reacting with metals, tend to gain electrons (typically attaining noble gas electron configuration) and become anions:

Nonmetal + Metal -> Salt

3Br2(l)+2Al(s)→2AlBr3(s)(2.11.4)

Compounds composed entirely of nonmetals are molecular substances (not ionic).

They generally form acidic or neutral oxides with oxygen that that dissolve in water react to form acids:

Physical Properties of Metalloids

State: They are all solid at room temperature.

Conduction: Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semi-conductors.

Luster: Silicon for example appears lustrous, but is not malleable or ductile (it is brittle - a characteristic of some nonmetals). It is a much poorer conductor of heat and electricity than the metals.

Solid Solutions: They can form alloys with other metals.

Chemical Properties of Metalloids

Their physical properties tend to be metallic, but their chemical properties tend to be non-metallic.

The oxidation number of an element in this group can range from +3 to -2, depending on the group in which it is located.

Trends in Metallic and Nonmetallic Character

Metallic character is strongest for the elements in the leftmost part of the periodic table, and tends to decrease as we move to the right in any period (nonmetallic character increases with increasing ionization values). Within any group of elements (columns), the metallic character increases from top to bottom (the ionization values generally decrease as we move down a group). This general trend is not necessarily observed with the transition metals.

2.10: Electron Affinities 2.12: Electronegativity

Recommended articles

2.1: Many-Electron Atoms

2.2: Electron Configurations

2.3: Electron Configurations and the Periodic Table

2.4: Development of the Periodic Table

2.5: Effective Nuclear Charge

The calculation of orbital energies in atoms or ions with more than one electron (multielectron atoms or ions) is complicated by repulsive interaction...

The LibreTexts libraries are Powered by otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. Have questions or comments? For mor

Explanation:

its D

Answer:

(A) Varying ability to conduct electric current.

Explanation:

The most useful property of metalloids is their varying ability to conduct electric current.

Metalloids are elements or substances that shares properties that transcends between those of a true metal and non-metal.

Based on their properties that straddles those of metals and non-metals, they find good use in electronic parts. Most importantly because they have varying ability to conduct electric current. They conduct current under certain conditions.

Which groups on the periodic table represent the s- block ?

Answers

Answer:

Groups 1 and 2.

Explanation:

The elements of Group 1 and Group 2 of the modern periodic table are called S block elements. The two types of s block elements are possible i.e. the elements with one electron (s1) or the elements with two electrons (s2) in their s-subshell.

Water contains 2 polar bonds and the molecule is polar
True
False​

Answers

TRUEEEEEEEEEEEEEEEEEEEEEEE

What does the electronegativity of an atom indicate?
A.
The tendency of the atom to pull on electrons
B.
The measurement of the charge of an ion
C.
The effect the valence electrons have on core electrons
D.
The energy required to gain or lose an electron

Answers

Answer:

A. The tendency of the atom to pull on electrons

Explanation:

Took the quiz for  A⃣   p⃣   e⃣   x⃣  , its A

Which three types of reactions yield a product that is a chemically bonded combination of reactants? replacement, polymerization, decomposition polymerization, decomposition, oxidation decomposition, synthesis, replacement oxidation, synthesis, polymerization

Answers

Answer:

oxidation, synthesis, polymerization

Explanation: I took the test

The three types of reactions are product that is a chemically bonded combination of reactants are oxidation, synthesis, polymerization

A chemical reaction is often described as when two or three elements are combined together to form a compound. The product of oxidation, synthesis, polymerization are simply said to chemically bonded because they are composed of different reactants (elements) that are combined together to form another.

Conclusively, we can therefore say that the three types of reactions are product that is a chemically bonded combination of reactants are oxidation, synthesis, polymerization

Learn more from:

https://brainly.com/question/14197404

Why series fatty acid carbons seen in double from?

Answers

Stearic acid is a fully saturated fatty acid with no carbon-carbon double bonds. (Bottom) Oleic acid is an unsaturated fatty acid.

Acetylene gas is often used in welding torches because of the very high heat produced when it reacts with oxygen gas, producing carbon dioxide gas and water vapor. Calculate the moles of oxygen needed to produce 0.095 of carbon dioxide. Be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.

Answers

Answer:

0.12 mol O₂

Explanation:

Step 1: Write the balanced combustion reaction

C₂H₂ + 2.5 O₂ ⇒ 2 CO₂ + H₂O

Step 2: Establish the appropriate molar ratio

We want to know the moles of oxygen needed to produce 0.095 moles of carbon dioxide. The molar ratio of O₂ to CO₂ is 2.5:2.

Step 3: Calculate the moles of oxygen needed to produce 0.095 moles of carbon dioxide

0.095 mol CO₂ × 2.5 mol O₂/2 mol CO₂ = 0.12 mol O₂

GIVING BRAINLIEST!
What kinds of observations can you make that might indicate a chemical change is taking place?

Answers

Color Change.

Production of an odor.

Change of Temperature.

Evolution of a gas (formation of bubbles)

Precipitate (formation of a solid)

Hope this helps!:)

How many moles of NH₃ can be produced from 4.81 moles of nitrogen in the following reaction:
N₂ (g) + 3 H₂ (g) → 2 NH₃ (g)

Answers

Answer:

9.62moles of NH₃

Explanation:

Given parameters:

Number of moles of nitrogen  = 4.81moles

Unknown:

Number of moles of  NH₃ = ?

Solution:

To solve this problem, we need to establish a balanced reaction equation:

            N₂  +  3H₂  →  2NH₃

Now, we can solve the problem by working from the known to the unknown.

          1 mole of N₂ produced 2 moles of NH₃

         4.81moles of N₂ will produce 2 x 4.81  = 9.62moles of NH₃


7: How many times can a cell divide?

Answers

Explanation:

60 times and it matters why they need to in order to divide

In Rutherford's Gold Foil Experiment, he discovered ? O neutrons O Protons O nucleus O electrons 4 5​

Answers

Answer:

Rutherford's gold foil experiment showed that the atom is mostly empty space with a tiny, dense, positively-charged nucleus. Based on these results, Rutherford proposed the nuclear model of the atom.

The initial concentration of reactants in a first order reaction is 0.27 M. The rate constant for the reactio is 0.75 s^-1. What is the concentration of reactants after 1.5sec?

Answers

Answer:

Final concentration = 0.019 M

Explanation:

Initial Concentration [A]o = 0.27M

Rate constant, k = 0.75 s^-1

Final concentration [A] = ?

Time, t = 1.5s

The relationship between the variables is given by the equation;

ln[A] = ln[A]o - kt

ln[A] = ln(0.27) - (0.75)(1.5)

ln[A] = - 1.309 - 1.125

ln[A] = - 2.434

[A] = 0.019 M

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