Chemical or physical change pls help

Answer:

a

Explanation:

is my lucky guess im sorry if im wrong good luck

Answer:A

Explanation: because The nucleus directs all of the cell's activities, including reproduction.

Answer:

Covalent

General Formulas and Concepts:

Chemistry - Compounds

Explanation:

Step 1: Define

NCl₃ - Nitrogen Trichloride

Step 2: Identify

Nitrogen is a nonmetal

Chlorine is a Halogen Gas

Step 3: Confirm

Nitrogen and the 3 Chlorines will have to share electrons and form a Covalent bond.

Answer:

The bond is ionic.

Explanation:

If a nonmetal and a metal bond, it's known as a characteristic of an ionic bond.

The answer above is false, Google "Is nitrogen trichloride an ionic compound" in order to find out why.

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Answer:

Ca=2,8,8,2

Ne=2,8

S=2,8,6

Explanation:

bc Ca valance no is 20

Ne """""""""""""""""10

S """""”"""""""""* 16

Answer: 8.31

Explanation: they told me it was correct

The value of R for 4.00 moles of an ideal gas at 25°C, 100L of volume and pressure of 99.1 kPa is 99.1 kPa.L / mol.°C.

Ideal gas equation is a hypothesis which tells about the behavior of gas at different conditions and it is represented as:

PV = nRT, where

P = pressure of ideal gas = 99.1 kPa

V = volume of ideal gas = 100 L

n = moles of ideal gas = 4 moles

T = temperature ideal gas = 25 °C

R = universal gas constant = ?

On putting these values on the above equation, we get

R = (99.1)(100) / (4)(25)

R = 99.1 kPa.L / mol.°C

Hence value of R for ideal gas is 99.1 kPa.L / mol.°C.

To know more universal gas constant, visit the below link:

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Answer:

It all really depends on the side group the amino acid is on! For instance, out of the  20 side groups used to make proteins, there are only two main groups: polar and non-polar

Answer:

b). silver (Ag)

Explanation:

If you look at the periodic table, you just need to look at the atomic number of the element, because the atomic number tells you how many protons there are in the nucleus of the element.

But do be careful because some periodic tables have the molar mass at the top left corner, but the one I use has the atomic number at the top left corner, so make sure you look for the atomic number and not the molar mass.

Answer:

Oxide of manganese, Potassium permanganate, Manganese bromide and manganese oxide.

Explanation:

1. Manganese dioxide

Its chemical formula is [tex]$MnO_2$[/tex]. It is +4 oxidation state. It is a black solid which is fairly stable.

2. Potassium permanganate

Its chemical formula is [tex]$KMnO_4$[/tex]. It is commonly used in the laboratories as oxidizing agent. They appear black in color.

3 Manganese bromide

Its chemical formula is [tex]$MnBr_2$[/tex]

4. Oxides of manganese

Chemical formula is [tex]$Mn_3O_4$[/tex]

The most stable state of Manganese is +2 oxidation state.

Answer:

Explanation:

The correct answer is sodium (Na)

Answer: 1169.298 L

Explanation: In order to go from grams to liters, you must find the moles first using the molar mass, 62.068 g/mol (found via google search). I will assume the ethylene glycol is in gas form so we can use the 22.4 L per mol conversion.

Using dimensional analysis, starting with the kg, we must convert to grams, then moles, then liters.

[tex]\frac{3.24 kg}{} * \frac{1000g}{1 kg} * \frac{1 mol}{62.068 g} * \frac{22.4 L}{1 mol}[/tex]

Multiply the top individually, then the bottom individually.

[tex]\frac{72576}{62.068}[/tex]

Divide out.

[tex]= 1169.298 L[/tex]

In the end, we get 1169.298 L of ethylene glycol.

Answer:

The water absorbs the thermal energy of the fire.

Explanation:

Thermal energy a form of energy that is produced when a rise in temperature causes atoms and molecules to move faster and collide with each other. It is a form of energy which involves the transfer of energy from regions of higher heat content to regions of lower heat content.

A burning wood fire has a higher heat content than water. Therefore, when water is thrown on a wood fire, the water will absorb the heat from the burning wood fire in order to raise its own heat content. since the wood fire has lost heat to water, it would eventually stop burning, whereas the water whose heat content has been raised may have some of its molecules absorbing so much heat that a change of phase occurs to the liquid phase.

Answer:

I had a amazing thanksgiving thanks for asking

Explanation:

Answer:

The history of water supply and sanitation is one of a logistical challenge to provide clean water and sanitation systems since the dawn of civilization. Where water resources, infrastructure or sanitation systems were insufficient, diseases spread and people fell sick or died prematurely.

Explanation:

Answer:a metal loses electrons and becomes a positive ion

Explanation:

The answer option which describes a step in the process of formation of an ionic bond is: A. A metal atom loses electrons and becomes a positive ion.

In Chemistry, the three (3) fundamental types of chemical bonds are:

An ionic bond can be defined as a type of chemical bond which involves a metallic element transferring one or more electrons to a non-metallic element, in order to become a positive ion.

This ultimately implies that, the formation of an ionic bond typically involves a metal atom losing its electrons to a non-metallic element, in order to become a positive ion.

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Answer:

107.9g

Explanation:

Given parameters:

Molar mass of Cu  = 63.5g/mol

Molar mass of Ag  = 107.9g/mol

Mass of reacting Cu  = 31.75g

Unknown:

Mass of Ag produced  = ?

Solution:

The reaction equation is given as;

    Cu + 2AgNO₃ →  Cu(NO₃)₂ + 2Ag

The equation is balanced.

We start by find the number of moles of the known;

  Number of moles  = [tex]\frac{mass}{molar mass}[/tex]  

  Number of moles of Cu  = [tex]\frac{31.75}{63.5}[/tex]   = 0.5moles

From the balanced equation;

       1 mole of Cu produced 2 moles of Ag;

      0.5 mole of cu will produce 0.5 x 2 mole of Ag  = 1 mole of Ag

Now;

 Mass of Ag  = number of moles x molar mass

 Mass of Ag  = 1 mole of Ag x 107.9g/mol  = 107.9g

Answer:

107.9

Explanation:

Answer:

138g

Explanation:

According to this question, sodium reacts with chlorine to form sodium chloride as follows:

Na(s) + Cl(g) → NaCl (aq)

According to the law of conservation of mass, matter can neither be created nor destroyed, but can only be transferred from one form to another. This means that the mass of the reactants in a chemical reaction must equate the mass of products of that reaction.

Hence, If 76g of sodium reacts with chlorine to produce 214g of sodium chloride, this means that to obey the law of conservation of mass, the mass in grams of chlorine that reacted is 214g - 76g = 138g

In this sense, the combined 76g of sodium and 138g of chlorine (reactants) will equate the 214g of sodium chloride (products) in obeisance to law of conservation of matter.

Answer:true

Explanation:

This statement is correct

Answer:

A). An atom is an indivisible hard-sphere.

Explanation:

The 'Atomic Theory' of Dalton is characterized as the earliest model(came in 1803) which described the atoms as the indivisible and resistant spheres. He used the example of watermelon to elaborate that the atoms of a specific element share similar characteristics and the atoms of distinct elements differ in their mass as well as their size. Thus, option A is the correct answer.

The statement that describes the earliest model of the atom is: A. An atom is an indivisible hard sphere.

An atom can be defined as the smallest, indivisible, basic unit of matter that forms all chemical elements.  Thus, an atom is the fundamental (basic) building blocks of matter i.e all physical and chemical substances.

Additionally, an atom defines or determines the structure of a chemical element.

Basically, an atom comprises three (3) main particles and these are;

The earliest (first model) of an atom was proposed by a notable English chemist called John Dalton. In the early 1800s, John Dalton adopted Democritus' theory to formulate the earliest (first model) of an atom.

Dalton's atomic theory described the atom of a chemical element as an impenetrable, movable, indivisible, very small (tiny) but movable hard sphere i.e it cannot be divided into subatomic or very tiny particles.

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Answer: so the answer is A

Explanation: The relationship between an object's mass (m), its acceleration (a), and the applied force (f) is F=ma. ... This law requires that the direction of the acceleration vector is in the same direction as the force vectors.

Answer:

Explanation:

Cobalt bromate is the name of this compound

The name of the given compound is Cobalt(III) bromate.

Explanation:

While naming compounds of a transition element :

Given

The molecule formula of a compound[tex]Co(BrO)_3[/tex]:

To find:

The name of the given compound formula

Solution:

The charge on the cobalt ion = +3

The charge on the bromate ion = -1

Cation in formula = [tex]Co^{3+}[/tex] = Cobalt cation

Anion in the formula= [tex]BrO^{-}[/tex] = Bromate ion

So, the name of the given compound is Cobalt(III) bromate.

Learn more about the naming of compounds here:

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Answer:

J.J.Thomson discovered negatively charged particles by cathode ray tube experiment in the year 1897. The particles were name electrons.

Answer:

A pure metal is any metal that has not been joined with any other metal

Explanation:

Answer:

Be cause of The fat

Explanation:

It’s just fat

Answer:

vinegar is acidic

water should be neutral but people say since it's pH 7,it will be more alkaline

salt solution is acidic

lemon juice is acidic

sugar solution is alkaline

soap is alkaline

Methyl orange will turn red with grapefruit juice.

Methyl orange will turn yellowish orange or lemme say red with oven cleaner

The addition of pure water to methyl orange will not have an effect on the color and the solution will still be around neutral pH and yellow in color.

Explanation:

Working on number 7

Answer:

D

Explanation:

usa testprep!!!!!

Answer:

false

Explanation:

Answer:

bromine, iodine, chlorine, flourine

Explanation:

thdy are all diatomic elements- meaning they can only exust with 2 elements. other diatomic elements include: (theres 7 btw)

-Bromine

-Iodine

-Nitrogen

-Chlorine

-Hydrogen

-Oxygen

-Flourine

Answer:Consider the reaction N2(g) + 3H2(g) =; 2NH3(g). If hydrogen gas is added to this system at equilibrium, will the reaction shift towards reactants