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2 years ago

Which sentence from the article BEST describes HOW fireworks produce colors in the sky?

Chemistry

1 answer:

aleksley [76]2 years ago

7 0

The answer is Abecaue it is the most specific on how

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Which pair of elements is most apt to form an ionic compound with each other?

sweet [91]

Ionic compounds are compounds that are formed together by a cation and an anion. A cation is an ion with a positive charge. For example, Na+ and Ca2+. An ion has a negative charge, like Cl- and OH-. There is a greater chance of forming an ionic compound when they have a great difference in electronegativity, the ability to attract electrons toward itself. In the periodic table, elements that are opposite to each other, more likely found in opposite sides, would be more apt to form an ionic compound. Example would be NaCl and CaCl2 or Ca(OH)2.

7 0

2 years ago

Consider the reaction:

stich3 [128]

Answer:

$\large \boxed{\text{-851.4 kJ/mol}}$

Explanation:

2Al(s) + Fe₂O₃(s) ⟶ Al₂O₃(s) + 2Fe(s); ΔᵣH = ?

The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is

$\Delta_{\text{r}}H^{\circ} = \sum \Delta_{\text{f}} H^{\circ} (\text{products}) - \sum\Delta_{\text{f}}H^{\circ} (\text{reactants})$

2Al(s) + Fe₂O₃(s) ⟶ Al₂O₃(s) + 2Fe(s)

ΔfH°/kJ·mol⁻¹: 0 -824.3 -1675.7 0

$\begin{array}{rcl}\Delta_{\text{r}}H^{\circ} & = & [1(-1675.7) + 2(0)] - [2(0) - 1(-824.3)]\\& = & -1675.7 + 824.3\\& = & \textbf{-851.4 kJ/mol}\\\end{array}\\\text{The enthalpy change is } \large \boxed{\textbf{-851.4 kJ/mol}}$

7 0

3 years ago

Suppose a species of snake is living in a certain area. Some of the snakes in the population are black and some are orange. Over

dybincka [34]

Answer:

The black snakes will survive and reproduce while the orange snakes die out.

Explanation:

The orange snakes will be easier to see by their prey and predators, and therefore will die out while the black snakes thrive because of their camouflage.

6 0

3 years ago

Read 2 more answers

The s orbitals are said to be non directional what does it mean

ser-zykov [4K]

s - orbitals have a spherical symmetry and the probability of finding an electron in an s orbital is equal for equal distance in x, y or z direction. i mean the probability of lets say an electron found at a distance 10 units from nuclues, its value will be same for x, y and z when u go 10 units distnace from nucleus in these directions. then the value at 5 units would be some value which also would be same for x,y and z.

Easier explanation is that if u place a ball, can u tell towards which axis it is oriented? no, its equally in all directions. So, non- directional.

However, if you have p- orbitals like dumb bells, a dumb bell can be oriented in three different directions, either x or y or z. see the pics.

3 0

3 years ago

Why is there a difference in the conductivity of pure solid NaC1 and of the 1.0 M NaC1 soulution

Basile [38]

That would be cause part of the sodium is pure and that means it still kind of has it properties when it was an element and that its i think.

7 0

3 years ago