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2 years ago

If there is a New Moon at midnight on October 1, when would the next New Moon occur?

1 answer:

8 0

Answer: C

Explanation: A lunar month is 29.53 earth days. Since an earth calendar as only integer days, it could be either 29 or 30 days later.

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Write isotopic symbols in the form AZX for each isotope. a. the copper isotope with 34 neutrons b. the copper isotope with 36 ne

krek1111 [17]

Explanation:

The form AZX denoted that;

Z = The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.

A = Mass Number ( Sum of Neutrons and Protons)

X represents the element.

A. the copper isotope with 34 neutrons

X = Cu

Atomic Number of Copper, Z = 29

Mass Number, A = 29 + 34 = 63

63.29.Cu

B. the copper isotope with 36 neutrons

X = Cu

Atomic Number of Copper, Z = 29

Mass Number, A = 29 + 36 = 65

65.29.Cu

C. the potassium isotope with 21 neutrons

X = K

Atomic Number of Potassium, Z = 19

Mass Number, A = 19 + 21 = 40

40.19.K

D. the argon isotope with 22 neutrons

X = Ar

Atomic Number of Argon, Z = 18

Mass Number, A = 18 + 22 = 40

40.18.Ar

5 0

2 years ago

In general, which attractions are stronger: intermolecular or intramolecular? Research and explain a quantitative comparison bet

murzikaleks [220]

Answer is: intramolecular attractions are stronger.

Intramolecular attractions are the forces between atoms in molecule.

There are several types of intramolecular forces: covalent bonds, ionic bonds.

Intermolecular forces are the forces between molecules. The stronger are intermolecular forces, the higher is boiling point of compound, because more energy is needed to break interaction between molecules.

There are several types of intermolecular forces: hydrogen bonding, ion-induced dipole forces, ion-dipole forces andvan der Waals forces.

Hydrogen bonds are approximately 5% of the bond strength of covalent C-C or C-H bonds.

Hydrogen bonds strength in water is approximately 20 kJ/mol, strenght of carbon-carbon bond is approximately 350 kJ/mol and strengh of carbon-hydrogen bond is approximately 340 kJ/mol.

20 kJ/350 kJ = 0.057 = 5.7 %.

8 0

3 years ago

30 points if you can help me with this chemistry question

PIT_PIT [208]

answer:

i am pretty sure you use cross charges for this.

so i think it is the third choice.

5 0

2 years ago

How many milliliters of 2.19 M H2SO4 are required to react with 4.75 g of solid containing 21.6 wt% Ba(NO3)2 if the reaction is

Setler [38]

Answer:

1.7927 mL

Explanation:

The mass of solid taken = 4.75 g

This solid contains 21.6 wt% $Ba(NO_3)_2$ , thus,

Mass of $Ba(NO_3)_2$ = $\frac {21.6}{100}\times 4.75\ g$ = 1.026 g

Molar mass of $Ba(NO_3)_2$ = 261.337 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{1.026\ g}{261.337\ g/mol}$

$Moles= 0.003926\ mol$

Considering the reaction as:

$Ba(NO_3)_2+H_2SO_4\rightarrow BaSO_4+2HNO_3$

1 moles of $Ba(NO_3)_2$ react with 1 mole of $H_2SO_4$

Thus,

0.003926 mole of $Ba(NO_3)_2$ react with 0.003926 mole of $H_2SO_4$

Moles of $H_2SO_4$ = 0.003926 mole

Also, considering:

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

Molarity = 2.19 M

So,

$2.19=\frac{0.003926}{Volume\ of\ the\ solution(L)}$

Volume = 0.0017927 L

Also, 1 L = 1000 mL

<u>So, volume = 1.7927 mL</u>

5 0

2 years ago

18 Reema observed that most of the fish in the pond of her village were gradually dying. She

juin [17]

Answer:

a. The fish are dying due to factory pollution making the water of the pond uninhabitable.

b. The pond can be neutralized by adding something basic to balance the pH levels of the pond, or by adding significant amounts of water to dillute the acidity of the pond.

3 0

3 years ago