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3 years ago

What are constellations

Chemistry

2 answers:

OlgaM077 [116]3 years ago

8 0

Stars that form shapes, or are connected together.

BigorU [14]3 years ago

7 0

Constellation is a group of stars that are considered to form imaginary outlines or meaningful patterns on the celestial sphere, typically representing animals, mythological people or gods, mythological creatures, or manufactured devices.

You might be interested in

What is the simplest whole number ratio of atoms in a molecule or formula unit called?

astra-53 [7]

The empirical formula

7 0

3 years ago

. A scientist placed a sample of lithium into a container of water. The scientist observed the lithium floating and making a buz

Alex73 [517]

Answer: The conclusion that best support the observation is that (A CHEMICAL CHANGE took place).

Explanation:

A chemical reaction is defined as the process by which two or more substances, which are often referred to as REACTANTS, combine through bond formation or dissociation of bonds to form new PRODUCTS. In this type of reaction, a CHEMICAL CHANGE occurred because a new substance is formed as a result of the chemical reaction that took place.

There are different characteristics of a reaction which shows that a chemical change has occurred, these includes:

--> Color Change

--> Production of an odor

--> Change of Temperature

--> Evolution of a gas (formation of bubbles)

-- Precipitate (formation of a solid)

From the chemical reaction in the given question, Lithium metals reacts slowly with water to form a colourless solution of lithium hydroxide (LiOH) and hydrogen gas (H2). Here we observe that the buzzing sound of formed gas bubbles shows that a gas was given off. Therefore in conclusion, a CHEMICAL CHANGE took place.

3 0

3 years ago

When enamel is remineralized with fluoride

WITCHER [35]

<h2>The required "option is d)".</h2>

Explanation:

Remineralization of enamel is a natural process and is of the same color.
The saliva contains calcium, phosphate, and fluoride which helps in the neutralisation of acids present in food.
Remineralization helps in improving the strength and functioning of the tooth by replacing calcium ions and flouride ions which were removed by demineralization.
It helps in prevention of cavity formation in teeth and strengthens the teeth by replacing loss of calcium ions, phosphate ions, and fluoride by fluorapatite crystals that are more resistant to acids.
Hence, the remineralized crystal is more resistant to acids.

6 0

4 years ago

What is the atom inventory for the following equation after it is properly balanced? ____K2S + ____CoCl2 Imported Asset ____KCl

Scilla [17]

Answer:

Reactants: K = 2, S = 1, Co = 1, Cl = 2; Products: K = 2, S = 1, Co = 1, Cl = 2

Explanation:

The reaction is a double replacement reaction so the anions (Cl⁻ and S²⁻) switch places.

1 K₂S + 1 CoCl₂ ⇒ 2 KCl + 1 CoS (balanced chemical equation)

On the reactants and products side, K = 2, S = 1, Co = 1, and Cl = 2.

Hope that helps.

5 0

3 years ago

At a certain temperature a 42.55% (v/v) solution of ethyl alcohol, C2H5OH, in water has a density of 0.9027 g mL-1. The density

swat32

Answer:

a. 7.187M.

b. 7.962m.

c. 0.1846

Explanation:

This solution contains 42.55mL of ethyl alcohol in 100mL of solution.

a. Molar concentration = Moles ethyl alcohol / L solution:

Moles ethyl alcohol -Molar mass: 46.07g/mol-

42.55mL * (0.7782g/mL) * (1mol / 46.07g) = 0.7187 moles ethyl alcohol

Liters solution:

100mL * (1L / 100mL) = 0.100L

Molar concentration: 0.7187mol / 0.100L = 7.187M

b. Molal concentration: Moles ethyl alcohol (0.7187moles) / kg solution

kg solution:

100mL * (0.9027g / mL) * (1kg / 1000g) = 0.09027kg

Molal concentration: 0.7187mol / 0.09027kg = 7.962m

c. Mole fraction: Moles ethyl alcohol / Moles ethyl alcohol + moles water

Moles water: -molar mass: 18.01g/mol-

Volume water = 100mL - 42.55mL = 57.45mL

57.45mL * (0.9949g/mL) * (1mol/18.01g) = 3.1736 moles water

Moles fraction:

0.7187 moles ethyl alcohol / 0.7187 moles ethyl alcohol+3.1736 moles water

= 0.1846

4 0

3 years ago