I need help with these 7 questions ASAP pls

Answer:  Mixtures can be physically separated but pure substances cannot be physically separated.

Explanation: Mixtures can be physically separated by using methods that use differences in physical properties to separate the components of the mixture, such as evaporation, distillation, filtration and chromatography. A pure substance, any compound or element, can't be separated into different atoms by physical methods. Pure substances are compounds and elements (made up of the same atom or same molecule respectively), while mixtures are an assortment of different substances put together. Hope this helps ^-^.

Pure substances cannot be physically separated but mixtures can be physically separated. Therefore, option (4) is correct.

Pure substances such as elements cannot be created by chemical reactions and cannot be broken down into simple substances. They have only one type of atom in the entire composition.

A pure substance consists of two or more elements that are chemically combined and has a fixed composition such kind of pure substance is called a compound. Pure substances can not be physically separated such as gold, silver, copper, etc.

A mixture is formed when two or more different substances are only physically combined or mixed together.  They are not formed by the chemical reaction so that a mixture can be separated physically into its original components.

A mixture cannot be formed from a single type of matter even a homogeneous mixture has two or more types of substances but the composition of the substance in the entire mixture is always the same.

Learn more about mixture and a pure substance, here:

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Answer:

thank you so much i really needed that

Explanation:

Answer:

2 metalliods....

1 metals

Answer:

432cm³

Explanation:

Given parameters:

Length  = 12cm

Height  = 6cm

Width  = 6cm

Unknown:

V = ?

Solution:

We have been given that;

                    V  = L x W x H

So;

                 V  = 12cm  x 6cm x 6cm  = 432cm³

Answer:

8.33m/s

Explanation:

Given parameters:

Distance traveled  = 500m

Time taken  = 60s

Unknown:

Speed of the sound  = ?

Solution:

The speed the sound can be derived using the expression below:

 Speed  = [tex]\frac{distance}{time}[/tex]  

So;

    Speed  = [tex]\frac{500}{60}[/tex]    = 8.33m/s

Answer:

Selection, in biology, the preferential survival and reproduction or preferential elimination of individuals with certain genotypes (genetic compositions), by means of natural or artificial controlling factors.

Explanation:

Hope it helps you

Answer:

24.58 m/s

Explanation:

Given that,

Speed of an object = 55 mph

We need to find the equivalent unit in m/s

We know that,

1 mile = 1609 m

1 hour = 3600 s

So,

[tex]55\ mph=\dfrac{55\times 1609\ m}{3600\ s}\\\\=24.58\ m/s[/tex]

So, the required speed is 24.58 m/s.

Answer:Two atoms of the same chemical element are typically not identical. First of all, there is a range of possible states that the electrons of an atom can occupy. Two atoms of the same element can be different if their electrons are in different states.

Explanation:This is not mine write it in your own words.

Answer:

potassium chloride.

Answer:  " 13.5 g Al " ;

                    →  that is:  "13.5 grams of aluminum."

____________________________

Explanation:

____________________________

Note: What is missing from the question is the "balanced chemical equation" for the "chemical reaction" that contains:

 The reactants:  "aluminum (Al) " ;  and "chlorine (Cl) " ;  and:

 The product:    "aluminum choloride (AlCl₃) " .

____________________________

The "balanced chemical equation" is:

____________________________

        2 Al   +   3 Cl₂   →   2 AlCl₃   ;

_____________________________

Note: The molecular weight of "aluminum (Al)" is:   " 26.98 g /mol " .

____________________________

So:  We call solve using a technique known as:  "dimensional analysis" :

____________________________

  0.500 mol AlCl₃ * [tex](\frac{2mol Al}{2mol AlCl_{3} }) * (\frac{26.98g Al}{1 mol Al}) = ?[/tex]

____________________________

Note:  The units of "mol AlCl₃" cancel out to "1' ; and:

          The  units of "mol Al" cancel out to "1" ; and we are left with:

____________________________

 " [tex]\frac{(0.500 * 2 * 26.98)}{2}[/tex]   g Al ["grams of aluminum"] ;

____________________________

Note: We can "cancel out the "2's" ; since "2/2 = 1 " ; and we have:

 →  (0.500 * 26.98) g Al ;

    = 13.49 g Al ;

         →  Round to 3 (Three) significant figures;

         →  Since:  "0.500" has 3 (Three) significant figures:

____________________________

   =  13.5 g Al ; that is:  "13.5 grams of aluminum."

____________________________

 Hope this is helpful!  

      Best wishes to you in your academic pursuits—and within the "Brainly" community!

____________________________

Explanation:

NH4Cl at 90°C _.70 a ... m aximum amount of solute that will dissolve at that specific temperature (no ... A mass of 100 g of NaNO3 is dissolved in 100 g of water at 80°C. Is the ... SO2, NH3, HCl.

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i have thids quuuuesstttttttiopn

Answer:

It's False

Explanation:

In a chemical reaction, reactants that are not used up when the reaction is finished are called excess reagents. The reagent that is completely used up or reacted is called the limiting reagent, because its quantity limits the amount of products formed.

Hope this helps you

Answer: false

Explanation:

Answer:

i believe its 5.2

Explanation:

Answer:

Number of protons

Explanation:

There are three sub atomic particles. These are;

- Protons

- Electrons

- Neutrons

Among these three particles, only one determines the identity of the element. This is the Protons. The number of protons which is also called the atomic number determines the identity of an element. For instance, atom with one proton is Hydrogen and n other element can have atomic number of one.

Explanation:

On the periodic table, we can find a wide range of elements from alkali metals, to the alkali earth metals, transition metals and through to the noble gases.

The alkali metals are found on the first group in the periodic table and they are group of metals. Also, the transition elements are also a group of metals.

Answer:

thi s is 4 ano

Explanation:

sjfdbbjjbfogfg

Answer:

the continental plate is bigger than the oceanic plate.

Explanation:

Answer:

128g

Explanation:

Given parameters:

Mass of carbon  = 48g

Mass of carbon dioxide  = 176g

Unknown:

Mass of oxygen that reacted  = ?

Solution:

Every chemical reaction must obey the law of conservation of mass. It states that "in a chemical reaction, matter is neither created nor destroyed" .

So;

     Mass of carbon + Mass of oxygen  = Mass of carbon dioxide

Mass of oxygen  = Mass of carbon dioxide  - Mass of carbon

Mass of oxygen  = 176  - 48  = 128g

Answer: 4

Explanation: if you move to spaces in a number line from 2 you would be at 4

M = 2 . 8 . 2

Valence Electron of M = 2

M ==>  M⁺²  +  2 e⁻

a. M⁺² +  OH⁻   ==>   M(OH)₂

b. M⁺² +  PO₄⁻³  ==>  M₃(PO₄)₂

Answer: c

Explanation: i think its right on edge

Answer:

That is correct.

Explanation:

Answer:

hot air rises and expanded the balloon

Explanation:

thats it.

Answer:

[tex] \frac{1839}{18} = 102.16[/tex]

Take 102.16 and multiply by avogadros #

and you get 6.33 × 10^25 otherwise A

Answer:

Answer is A

Explanation:

I just took this.