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3 years ago

PLEASE HELP WILL MARK BRAINLIEST!

2 answers:

8 0

A substance is essentially a species of matter having a definite chemical composition . A number of substances can combine to form a mixture. Pure substances are composed of a single element or compounds. Combinations of different substances are called mixtures. Homogeneous mixtures are mixtures of two or more compounds (or elements) that are not visually distinguishable from each other.

In the classical physics observed in everyday life, matter is any substance that has mass and takes up space by having volume. This includes atoms and anything made up of these, but not other energy phenomena or waves such as light or sound. More generally, however, in (modern) physics, matter is not a fundamental concept because a universal definition of it is elusive; for example, the elementary constituents of atoms may be point particles, each having no volume individually.

garik1379 [7]3 years ago

5 0

Answer:

Pure substances are further broken down into elements and compounds. Mixtures are physically combined structures that can be separated into their original components. ... A heterogeneous mixture is a mixture of two or more chemical substances where the various components can be visually distinguished.

Explanation:

hopes this helps. :)

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SOMEONE WHO IS GOOD AR CHEMISTRY PLEASE MESSAGE ME!!

galina1969 [7]

Answer:

i am

Explanation:

4 0

4 years ago

What is the percent composition of Ca(OH)2? 37.7% Ca, 53.0% O, and 10.3% H 45.5% Ca, 38.2% O, and 16.3% H 54.0% Ca, 43.0% O, and

Naddik [55]

The molar mass of Calcium hydroxide is 74 g/mol

To find the percent composition we have to find the number of atoms of each element in the formula .

So there’s

Calcium - 1

Oxygen - 2

Hydrogen - 2

Then have to multiply the relative atomic mass of each element by the number of atoms

Ca - 40 g/mol x 1 = 40

O - 16 g/mol x 2 = 32

H - 1 g/mol x 2 = 2

Then To find percent composition of each element we have to divide the mass of each element in the formula by the relative molecular mass of calcium hydroxide

Ca - 40 / 74 x 100 % = 54.0%

O - 32 / 74 x 100 % = 43.2 %

H - 2 / 74 x 100 % = 2.7%

From the options given correct answer is 3rd option

54.0% Ca , 43.0% O and 2.7 % H

6 0

4 years ago

A Bronsted-Lowry acid is defined as a substance that ________. A Bronsted-Lowry acid is defined as a substance that ________. in

Anestetic [448]

Answer: A Bronsted-Lowry acid is defined as a substance that acts as a proton donor.

Explanation:

A substance that is able to donate a proton or hydrogen ion to another substance is a Bronsted-Lowry acid.

For example, HCl is a Bronsted-Lowry acid as it dissociates to give a hydrogen ion.

$HCl \rightleftharpoons H^{+} + Cl^{-}$

Thus, we can conclude that a Bronsted-Lowry acid is defined as a substance that acts as a proton donor.

3 0

3 years ago

Question 22

ruslelena [56]

Answer:

O2, oxygen.

Explanation:

Hello.

In this case, for the undergoing chemical reaction, we need to compute the moles of CO2 yielded by 85 g of CH4 (molar mass = 16 g/mol) and by 320 g of O2 (molar mass 32 g/mol) via the following mole-mass relationships:

$n_{CO_2}^{by\ CH_4}=85gCH_4*\frac{1molCH_4}{16gCH_4} *\frac{1molCO_2}{1molCH_4} =5.3molCO_2\\\\n_{CO_2}^{by\ O_2}=320gO_2*\frac{1molO_2}{32gO_2} *\frac{1molCO_2}{2molO_2} =5molCO_2$

Considering the 1:2:1 among CH4, O2 and CO2. Therefore, since 320 g of O2 yield the smallest amount of CO2 we infer that the limiting reactant is O2.

Best regards.

5 0

3 years ago

what is the difference between atomic number and atomic mass, and what do they tell you about the atom

Anastasy [175]

<span>Mass number is the number of protons and neutrons in an atom, and it tells us about the mass of the atom in amu, or atomic mass units. </span>

<span>Atomic mass is the average mass of all the isotopes of a certain type</span>

3 0

3 years ago