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3 years ago

Which statement is true about the elements present in a pure substance?

Chemistry

2 answers:

djverab [1.8K]3 years ago

8 0

I'm not sure but I think is C or D.

Makovka662 [10]3 years ago

4 0

Answer: Option (D) is the correct answer.

Explanation:

An element is defined as a substance that contains atoms of one type.

For example, a piece of sodium metal will contain only atoms of sodium.

Therefore, it is a pure substance. Whereas a compound is a substance that consists of two or more different atoms in similar composition.

For example, $CaCl_{2}$ is a compound.

When elements change into compounds then they tend to change their chemical properties.

Hence, we can conclude that the statement they can only be separated by chemical methods, is true about the elements present in a pure substance.

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The arrows below represent the velocities of two vehicles. Which claim explains why the velocity of each vehicle is a vector qua

ollegr [7]

Answer:

It has direction and size.

Explanation:

All physical quantities are generally grouped into two;

i) Vector quantities

ii) Scalar quantities

Vector quantities are those quantities that has both magnitude (size) and direction.

Scalar quantities are those quantities that has magnitude (size) and no direction.

Velocity is a vector quantity because it has direction and size.

4 0

2 years ago

37.9 grams of an unknown substance undergoes a temperature increase of

jenyasd209 [6]

Answer:

1.023 J / g °C

Explanation:

m = 37.9 grams

ΔT = 25.0*C

H = 969 J

c = ?

The equation relating these equation is;

H = mcΔT

making c subject of formulae;

c = H / mΔT

c = 969 J / (37.9 g * 25.0*C)

Upon solving;

c = 1.023 J / g °C

4 0

3 years ago

If sodium is burned in chlorine gas, a compound is formed that dissolves in water. What colour will the solution be?

Alchen [17]

If sodium is burned in chlorine fuel, a compound is formed that dissolves in water. the solution be: Bright yellow mild

Chlorine is a yellow-green gas at room temperature. Chlorine has a smelly, annoying scent similar to bleach that is detectable at low concentrations. The density of chlorine gasoline is about 2.5 times extra than air, so one can reason it to initially stay near the floor in regions with little air movement.

Chlorine gasoline can be recognized by using its smelly, anxious smell, which is like the scent of bleach. The sturdy scent may additionally provide a good enough caution to human beings that they have been uncovered. Chlorine fuel appears to be yellow-green in color. Concentrations of approximately 400 ppm and past are commonly fatal over a half-hour, and at 1,000 ppm and above, fatality ensues within only some mins. A spectrum of scientific findings can be present in those uncovered to excessive tiers of chlorine.

Learn more about Chlorine here:

brainly.com/question/25190915

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6 0

1 year ago

How can indicator be used to determine if a solution is an acid or base

dalvyx [7]

Answer:

To tell if something is an acid or a base, you can use a chemical called an indicator. An indicator changes color when it encounters an acid or base. There are many different types of indicators, some that are liquids and others that are concentrated on little strips of "litmus" paper.

Explanation:

8 0

2 years ago

What is the molarity of a solution composed of 5.85 g of potassium iodide, KI, dissolved

Troyanec [42]

Answer:

0.282 M

General Formulas and Concepts:

Chemistry - Solutions

Reading a Periodic Table
Using Dimensional Analysis
Molarity = moles of solute / liters of solution

Explanation:

Step 1: Define

5.85 g KI

0.125 L

Step 2: Identify Conversions

Molar Mass of K - 39.10 g/mol

Molar Mass of I - 126.90 g/mol

Molar Mass of KI - 39.10 + 126.90 = 166 g/mol

Step 3: Convert

$5.85 \ g \ KI(\frac{1 \ mol \ KI}{166 \ g \ KI} )$ = 0.035241 mol KI

Step 4: Find Molarity

M = 0.035241 mol KI / 0.125 L

M = 0.281928

Step 5: Check

We are given 3 sig figs. Follow sig fig rules and round.

0.281928 M ≈ 0.282 M

7 0

3 years ago