Which of these is a chemical property of a substance?

The chemical formula for the compound strontium sulfide, which contains Sr2+ and S2– ions, is

Slav-nsk [51]

The chemical formula for the compound strontium sulphide would be SrS.

3 0

3 years ago

Who proposed the "Law of Octaves" for organizing events?

djyliett [7]

b

Explanation:

February 7, 1863, was the day John Newlands published a paper outlining what would be known as “The Law of Octaves”. Newlands discovered if he ordered the known elements by increasing atomic weight, the chemical properties of the elements would be similar for every eighth group

5 0

3 years ago

The bond between which two atoms has the greatest degree of polarity

Alenkasestr [34]

Answer:

By comparing the bonds between C-H and O-H, the O-H bond has the greatest degree of polarity.

Explanation:

Based on bond electronegative values which is a measure of the ability of a atom in a chemical bond to pull the shared electrons closer to its self.

The electronegativity of an element characterizes the elements chemical reaction.

From the available bonds

Oxygen has an electronegativity value of 3.44 and Carbon 2.55, while Hydrogen has an electronegativity value of 2.20

Therefore the bond between carbon and hydrogen is much less polar than between oxygen and hydrogen.

The bond between oxygen and hydrogen has the greatest polarity.

6 0

3 years ago

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. how much calcium is contained in 45.0 g of c

kolbaska11 [484]

In a sample of pure calcium fluoride of mass 15.0 g, 7.70 g of calcium is present. First convert the mass into number of moles as follows:

$n=\frac{m}{M}$

Here, m is mass and M is molar mass.

Molar mass of Ca is 40 g/mol, putting the values,

$n=\frac{7.70 g}{40 g/mol}=0.1925 mol$

Similarly, molar mass of $CaF_{2}$ is 78.07 g/mol thus, number of moles will be:

$n=\frac{15.0 g}{78.07 g/mol}=0.1921 mol$ .

Thus, 0.1921 mol of $CaF_{2}$ have 0.1925 mol of Ca, or 1 mole of $CaF_{2}$ will have approximately 1 mole of Ca.

Now, mass of Ca needs to be calculated in 45.0 g of $CaF_{2}$ . Converting mass into number of moles first,

$n=\frac{45.0 g}{78.07 g/mol}=0.5764 mol$

Thus, number of moles of Ca will also be 0.5764 mol, converting number of moles into mass,

$m=n\times M=0.5764 mol\times 40 g/mol=23.06 g$

Therefore, mass of Ca will be 23.06 g.

6 0

3 years ago

Choose all that apply. As glaciers melted at the end of the last Ice Age:

Kaylis [27]

As glaciers melted at the end of the last Ice Age worldwide sea level increased immensely and river plains were flooded. Glaciers are floating bodies of ice. Ice is frozen water. When glaciers started melting water that had been frozen for decades or centuries was released back into the ocean. That lead to an increase in sea level. This also led to river plains being drowned/flooded. Therefore, the answer is 1 and 2.

3 0

3 years ago

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