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3 years ago

Really need help!

2 answers:

7 0

The magnitude of a star as it would appear to a hypothetical observer at a distance of 10 parsecs or 32.6 light-years. This rates how visible celestial bodies are when they are all viewed from the same distance. Luminosity: The brightness of a star in comparison with that of the sun.

vovangra [49]3 years ago

7 0

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Which of the following elements are more reactive than the others.

Rama09 [41]

The answer is D-sodium!

3 0

2 years ago

How many moles are there in 3.3 grams of NH4SO2

slavikrds [6]

1.69x10 22 molecules

8 0

2 years ago

What are some visible signs of an acid-base reaction?

marta [7]

I think one of the signs is <span>water and salt are formed

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6 0

2 years ago

What is the molarity (M) of the following solutions?

Dennis_Churaev [7]

Answer:

The molarity (M) of the following solutions are :

A. M = 0.88 M

B. M = 0.76 M

Explanation:

A. Molarity (M) of 19.2 g of Al(OH)3 dissolved in water to make 280 mL of solution.

Molar mass of Al(OH)3 = Mass of Al + 3(mass of O + mass of H)

= 27 + 3(16 + 1)

= 27 + 3(17) = 27 + 51

= 78 g/mole

$Al(OH)_3$ = 78 g/mole

Given mass= 19.2 g/mole

$Mole = \frac{Given\ mass}{Molar\ mass}$

$Mole = \frac{19.2}{78}$

Moles = 0.246

$Molarity = \frac{Moles\ of\ solute}{Volume\ of\ solution(L)}$

Volume = 280 mL = 0.280 L

$Molarity = \frac{0.246}{0.280)}$

Molarity = 0.879 M

Molarity = 0.88 M

B .The molarity (M) of a 2.6 L solution made with 235.9 g of KBr

Molar mass of KBr = 119 g/mole

Given mass = 235.9 g

$Mole = \frac{235.9}{119}$

Moles = 1.98

Volume = 2.6 L

$Molarity = \frac{Moles\ of\ solute}{Volume\ of\ solution(L)}$

$Molarity = \frac{1.98}{2.6)}$

Molarity = 0.762 M

Molarity = 0.76 M

4 0

2 years ago

Which of these elements has an atom with the most stable outer electron configuration? * Cl Ca Ne Na

SashulF [63]

Answer:

Neon (Ne) has the most stable outer electron configuration because the outer electron is completely filled and it has octet structure

Explanation:

The configuration of these elements is as follows;

Cl₁₇ = 2, 8,7 (the outer electron is 7)

Ca₂₀ = 2,8,8,2 (the outer electron is 2)

Ne₁₀ = 2,8 (the outer electron is 8)

Na₁₁ = 2,8,1 (the outer electron is 1)

Based on the outer electron value above, Neon (Ne) has the most stable outer electron configuration because the outer electron is completely filled and it has octet structure.

6 0

2 years ago