Another real-world example of a change is rust. Rust is iron oxide (Fe2O3), which results when iron is exposed to oxygen in the air. What are some indicators of rusting? Check all that apply. A) production of light B) color change C) formation of a solid D) formation of a gas

Answer:

Explanation:

This question seeks to test the knowledge of separation techniques.

From the narration in the question, the first separation to be done is the removal of Iron fillings by the use of magnet (magnetic separation). Since Iron is magnetic, the iron fillings will be attracted by the magnet hence removing the iron fillings from the mixture.

The second constituent to be removed will be the copper pieces by the use of a sieve (sieving). Copper pieces have relatively larger sizes than sand and common salt, hence a sieve (which separates particles based on size) can be used to remove the copper pieces from the mixture.

What will be left in the mixture after the processes above will be salt and water. This mixture will have to be dissolved in water; the salt will dissolve in water while the sand will not. After which, filtration will be done to remove the sand which will be collected on the filter paper as filtride and the salt solution will pass through the filter paper as filtrate.

The salt solution can then be evaporated to dryness to retrieve the solid salt from the solution.

The amount of salt in the mixture can then be measured using a weighing balance.

Some of safety measures to be taken during the course of this experiment includes performing the experiment in an airtight and controlled environment. Lab coat and hand gloves should be worn during the course of the experiment. The evaporation to dryness should not be done close to an inflammable material/substance

Answer:

Option A. 231 90Th

Explanation:

Please see attached photo for explanation

Answer:

Explanation:

Solids have a fixed shape and occupy a fixed volume. because the particles in liquid are so close together,liquids do'not easily compress,so their volume is fixed. gases can also flow, so they occupy the shape of the whole  container.

Answer:

525000000

Explanation:

[tex]1.500 \times {10}^{3} = 1500 \\ 3.50 \times {10}^{5 } = 350000 \\ 1500 + 350000 = 525000000[/tex]

Answer:

so you know what to do and you know the rules

Explanation:

Answer:

El reactivo limite es [tex]NH_3[/tex] y la cantidad de urea producida es 881.58 g

Explanation:

Podemos empezar con la reacción:

[tex]2NH_3~+~CO_2~->~(NH_2)_2CO~+~H_2O[/tex]

Tenemos 2 átomos de nitrógeno en ambos lados, 1 átomo de carbono en ambos lados, 2 átomos de oxigeno en ambos lados y  6 átomos de hidrógeno en ambos lados. Por lo tanto la reacción esta balanceada.

Ahora, para hallar el reactivo limite necesitamos seguir los siguientes pasos:

1) Convertir a moles usando la masa molecular de cada compuesto ( 17 g/mol para el amoniaco y 28 g/mol para el dióxido de carbono).

2) Usando el la relación molar entre cada compuesto con la urea podemos calcular las moles de urea ( para el amoniaco la relación es 2:1 y para el dióxido de carbono la relación es 1:1).

3) Finalmente, usando la masa molar de la urea (60 g/mol) podemos calcular la masa de urea.

[tex]500~g~NH_3\frac{1~mol~NH_3}{17~g~NH_3}\frac{1~mol~(NH_2)_2CO}{2~mol~NH_3}\frac{60~g~(NH_2)_2CO}{1~mol~(NH_2)_2CO}=881.58~g~(NH_2)_2CO[/tex]

[tex]1000~g~CO_2\frac{1~mol~CO_2}{28~g~CO_2}\frac{1~mol~(NH_2)_2CO}{1~mol~CO_2}\frac{60~g~(NH_2)_2CO}{1~mol~(NH_2)_2CO}=1364.6~g~(NH_2)_2CO[/tex]

El elemento que tiene la menor cantidad de urea se da en el calculo del amoniaco. Por lo tanto, el reactivo limite es el amoniaco y la cantidad de urea producida es 881.58 g

Espero que sea de ayuda!

Answer:

Compressibility means: being able to basically squish something easier. Like water, water can be reduced in volume or size under pressure When that water expands, it turns into a gas.

Explanation:

Answer:

Volume of the rock, V = 2 mL

Explanation:

It is given that,

Water filled in a graduated cylinder is 3 mL

She  then drops a small rock into the cylinder and the water  level rises to the 5 mL mark

We need to find the volume of the rock.

The volume of the rock is equal to the difference in volume mark. So,

V = 5 mL - 3 mL

V = 2 mL.

Answer:

Density

Explanation:

Answer:

B.

Explanation:

Solids vibrate in a fixed position because they keep their shape. Liquids take the shape of their container, so A cannot be the answer. Solids do have a definite volume, so D is not your answer.

Answer:The two types of chemical bonds that atoms can form to achieve stability are called ionic bonds and covalent bonds. Does this help

Explanation:

Answer:

The correct option is;

c. The scientist can make and record observations

Explanation:

Empirical evidence are evidences obtained by direct observation, sensual perception or direct measurement. It is the processed and useful data gathered and stored in a material form or documented to provide record of the measurement.

With the aid of empirical evidence, it is possible for researchers to find answers to question regarding topics that can vastly impact every day life.

With empirical evidence, it is possible to determine the effects of treatment in a study such as the invention of working car safety devices such as seat belts and airbags.

Answer:

27g.

Explanation:

M = D x V

M = 2.7 x 10

M = 27.

Answer:

Litre (L) , Centimetre (cm) , Kilogram (Kg), Seconds (s) and Kelvin (K)

Explanation:

The units are used for the following measurement;

Litre = Volume

Centimetre = Length

Kilogram = Mass

Seconds = Time

Kelvin = Temperature

Answer:

See explanation

Explanation:

When we are comparing the effect of H3O^+ on the precipitation of a salt of a weak acid such as CaC2O4(s) and that of a strong acid such as AgCl(s) or CaSO4(s), we discover that H3O^+ has more effect on the precipitation of the salt of a weak acid.

This is because, anions of the weak acid combine with H^+ from H3O^+ thereby decreasing the concentration of the anion of the salt of the weak acid and increasing the solubility of the precipitate.

Answer:

N2 + O2 → 2NO is an oxidation-reduction reaction.

Explanation:

An oxidation-reduction reaction (also know as Redox reaction) is a type of chemical reaction that involves a transfer of electrons between two species. It occurs when the oxidation number of a molecule, atom, or ion changes by gaining or losing an electron.

We will consider the equations one after the other.

Oxidation numbers of the individual element on the reactant side:

KOH : K = +1, O = -2, H = +1

HNO3 : H = +1, N = +5, O = -2

Oxidation numbers of the individual element on the product side:

H2O: H = +1, O = -2

KNO3: K = +1, N = +5, O = -2

There is no change in the oxidation numbers, hence, it is not an oxidation-reduction reaction.

Oxidation numbers of the individual element on the reactant side:

CaCl2 : Ca = +2, Cl = -1

Na2SO4: Na = +1, S = +6, O = -2

Oxidation numbers of the individual element on the product side:

CaSO4: Ca = +2, S = +6, O = -2

NaCl: Na = +1, Cl = -1

There is no change in the oxidation numbers, hence, it is not an oxidation-reduction reaction.

Oxidation numbers of the individual element on the reactant side:

AgNO3: Ag = +1, N = +5, O = -2

NaCl: Na = +1, Cl = -1

Oxidation numbers of the individual element on the product side:

AgCl: Ag = +1, Cl = -1

NaNO3: Na: +1, N = +5, O = -2

There is no change in the oxidation numbers, hence, it is not an oxidation-reduction reaction.

Oxidation numbers of the individual element on the reactant side:

Al2(SO4)3: Al =+3, S = +6, O = -2

KOH: K = +1, O = -2, H = +1

Oxidation numbers of the individual element on the product side:

Al(OH)3: Al =+3, O = -2, H = +1

K2SO4: K = +1, S = +6, O = -2

There is no change in the oxidation numbers, hence, it is not an oxidation-reduction reaction.

Oxidation numbers of the individual element on the reactant side:

N2: N = 0

O2: O = 0

Oxidation numbers of the individual element on the product side:

NO: N = +2, O = -2

There are changes in the oxidation numbers, hence, it is an oxidation-reduction reaction.

The following is an oxidation-reduction reaction - N2 + O2 → 2NO

Oxidation numbers represent the potential charge of an atom in its ionic state. If the oxidation number decreases in a reaction, it is reduced. If an atom's oxidation number increases, it is oxidized.

= > Oxidation state of N in the reactant is 0

=> Oxidation state of N in the product is +2

So, N is oxidized

=> Oxidation state of O in the reactant is 0

=> Oxidation state of O in the product is -2

So, O is reduced

Thus, the following is an oxidation-reduction reaction - N2 + O2 → 2NO

Learn more:

https://brainly.com/question/11672211

Answer:1

Explanation:

Answer: c

Explanation:

Disposed of.... etc.

Answer:

The diagram is incorrect because there is only a single type of particle at the center of the atom.

Explanation:

The small circle at the centre of the sphere which contains six light gray spheres and six dark gray spheres represents the nucleus of the atom which is found at the centre of the atom.

The nucleus contains only one type of particle which is the proton. Hence the representation of two particles at the centre of the circle makes the model incorrect.

Answer:

D-  The diagram is correct because all electrons can be accommodated in two electron clouds around the nucleus.

Explanation:

This is the correct answer because i just took the pre-quiz and tried B and A and they were both incorrect and C just doesnt make any sense so yeah hope it helped :)

Answer:

d

Explanation:

'Heterogeneous Mixture' is characterized as 'a mixture that has more than one phase and its components are distinct visibly.'

The human being serves as an illustration of:

D). heterogeneous mixture

Learn more about 'heterogeneous' more:

brainly.com/question/5924138

Answer:

a method of procedure that has characterized natural science since the 17th century, consisting in systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.The basic steps of the scientific method are: 1) make an observation that describes a problem, 2) create a hypothesis, 3) test the hypothesis, and 4) draw conclusions and refine the hypothesis.

Explanation:

the scienticif Method and the second step of the scientific

Answer:

Viruses are considered at the borderline of living and non-living because they show both the characteristics of living and a non-living. As they react like non-living in the free atmosphere but when they enter the body of a living organism then they show the features of a living organism and start reproduction.

Answer:

because they become living inside the body of living organisms.

Explanation:

their body is composed of only DNA/RNA enclosed in protein capsule. they use host's DNA to replicate their own DNA/RNA. the below diagram is structure of RNA bacteriophage virus

Explanation:

We know that,

1 mile = 1609.34 m

We need to find how many meters are present in the 12.45 miles. To find it use unitary method as follows :

12.45 mile = 1609.34 × 12.45

12.45 mile=20036.283 meters

or

[tex]12.45\ mile=2.0036\times 10^4\ m[/tex]

Hence, this is the required solution.

Answer: 2nd one

Explanation:

PLATO

Answer:

1.72 g/ml

Explanation:

If our aim is to determine the density of the metal ore, then;

Mass of the metal ore= 9.00 g

Volume of the ore= volume of water displaced = 26.47 - 21.25 = 5.22 ml

Density of the ore= 9.00 g/5.22 mk

Density of the ore= 1.72 g/ml

Answer:

C)peer review

Explanation:

Peer review involves the evaluation of scientific research work by other professionals working in the same field. It is one of the stages a manuscript passes through before it is published in any reputable journal.

Peer review is important because it ensures that only high quality and original scientific research is published for the consumption of other professionals in the same field.

Answer: