CHEMISTRY MIDDLE SCHOOL

Which of the following is a physical change?-Burning
-Rusting
-Freezing
-Oxidation

Answers

Answer 1
Answer: Freezing is a physical change caused by temperature. 
The others cannot be undone easily, because the chemical structure has changed.

Related Questions

How do i describe how a constant volume calorimeter can be used to measure the heat transferred from a burning piece of coal to cool water.
Definition of mitochondria
The volume of a gas at 99.0 kPa is 300.0 mL. If the pressure is increased to 188kPa, what will be the new volume?
Can wind energy be used in transportation
What conclusion can be drawn from the statement that an element has a high ionization energy and small atomic size?A) The element is most likely from Group 1A or 2A and in period 1 or 2B) The element is most likely from Group 2A or 3A and in period 2 or 3.C) The element is most likely from Group 4A or 5A and in period 4 or 5.D) The element is most likely from Group 6A or 7A and in period 6 or 7​

What is a tough, rigid, outer covering that protects some cells and gives them shape?

Answers

it iscalled the "cell wall"

Complete the paragraph to describe the characteristics of a silicon tetrahydride molecule (SiH4). The Lewis structure and table of electronegativities are given.

Answers

Answer: The correct answer is polar, tetrahedral and non-polar.

Explanation:

It is given a compound which is silicon tetrahydride having formula SiH_4

The electronegativities of silicon and hydrogen are 1.9 and 2.1 respectively.

Difference in electronegativity = 2.1 - 1.9 = 0.2

From above, some difference in the electronegativities of the atoms is there. This means that bond polarity of this molecule is polar. If the difference would have been 0, the bond polarity of the molecule is taken as non-polar.

  • To determine the molecular shape of the given molecule, we calculate the hybridization of this molecule. The equation used for this is:  

\text{Number of electrons}=(1)/(2)[V+N-C+A]

where,  

V = number of valence electrons present in central atom i.e. Silicon = 4

N = number of monovalent atoms bonded to central atom = 4

C = charge of cation = 0

A = charge of anion = 0

Putting values in above equation, we get:  

\text{Number of electron pairs} =(1)/(2)[4+4-0+0]=4

As, the total number of electron pairs is 4, this means that the hybridization of this molecule will be sp^3 and the molecular shape will be tetrahedral.

  • The net dipole moment of the molecule is 0 because of the symmetry of the molecule. Thus, the molecule is considered as a non-polar molecule.

Hence, the correct answer is polar, tetrahedral and non-polar.

Students are completing a table about a particular subatomic particle that helps make up an atom.A 3-column table with 2 rows. The first row has entries Mass (a m u), location, charge. The second row has entries 1/2,000, nothing, has a charge.

What best explains how they should complete the table?

with “Inside the nucleus,” because the particle is a proton
with “Inside the nucleus,” because the particle is a neutron
with “Outside of the nucleus,” because the particle is a proton
with “Outside of the nucleus,” because the particle is an electron

Answers

Answer:

with “Outside of the nucleus,” because the particle is an electron

Explanation:

The table is best completed with “Outside of the nucleus,” because the particle is an electron.

The particle being described is an electron.

Electrons are negatively charged particles with a mass that is about (1)/(2000) of protons and neutrons

Mass(a.m.u)                         location                              charge

      (1)/(2000)                        outside of the nucleus                   negative charge

Electrons orbits round the nucleus in distinct energy levels.

Final answer:

The subatomic particle described in the table is an electron, which is found outside of the nucleus of an atom.

Explanation:

The particle described in the table has a mass of 1/2,000 atomic mass units (a.m.u) and carries a charge. Based on this information, we can conclude that the particle being described is an electron. Electrons are negatively charged subatomic particles that orbit the nucleus of an atom, meaning they are found outside of the nucleus. Therefore, the correct entry for the location column in the table should be Outside of the nucleus.

Learn more about subatomic particles here:

brainly.com/question/32192242

#SPJ3

Whats is a chemical change of a paper bag

Answers

Burning it. That causes a chemical reaction. 
Combustion will cause a chemical change in paper.

This is because the carbon compounds are being oxidized into carbon dioxide and water vapour (or h2o, same thing).

Which type of energy transfer occurs when water is heated on a stove

Answers

Hello User,

The type of energy that occurs when water is heated on stove is heat transfer. Heat transfer is the exchange of thermal energy.

A mole or fraction of a mole represents a ____ number of atoms or molecules.A : specific

B : nonspecific

Answers

Answer:

specific

Explanation:

a mole represents the amount of grams it takes to have avogadro's number

Answer:

A is your answer

Explanation:
Other Questions
Can formaldehyde molecules dissolve well in water?
Which of the following electromagnetic waves are listed in the correct order from longest wavelength to shortest wavelength? A.infrared, ultraviolet, visibleB.visible, infrared, ultravioletC.ultraviolet, visible, infraredD.infrared, visible, ultraviolet
The following mechanism has been proposed for the gas-phase reaction of chloroform (CHCl3) and chlorine:Step 1: Cl2(g)⇌2Cl(g)(fast)Step 2: Cl(g)+CHCl3(g)→HCl(g)+CCl3(g)(slow)Step 3: Cl(g)+CCl3(g)→CCl4(fast)What is the overall rate constant?