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3 years ago

Can someone help me on number 7

Chemistry

1 answer:

Artist 52 [7]3 years ago

3 0

The answer is "C" because all isotopes have a different mass number. The number of protons does not change. The mass of electrons is negligible. Thus, the number of neutrons changes.

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The basic principle of energy is:

nevsk [136]

Answer:

3) Neither created nor destroyed. Only converted.

Explanation:

8 0

2 years ago

Which of the following molecules can form hydrogen bonds? Group of answer choices NH3 NaH HI BH3 CH4

Len [333]

Answer:

NH₃

Explanation:

The hydrogen bond is a specially strong type of dipole-dipole interaction. For a hydrogen bond to occur, a molecule must have a hydrogen atom and a very electronegative atom, such as nitrogen, oxygen or fluorine. The hydrogen atom has a positive charge density while the heteroatom has a negative charge density.

<em>Which of the following molecules can form hydrogen bonds? </em>

NH₃ YES

NaH NO

HI NO

BH₃ NO

CH₄ NO

8 0

4 years ago

You are holding four identical balloons each containing 10.0g of a different gas. The balloon containing which gas is the larges

Vaselesa [24]

Answer:

Hydrogen, H_2

Explanation:

mass of each gas is 10.0 g

number of mole = mass/ molar mass

number of moles is directly proportional to volume at constant temp and pressure

this implies that the volume is inversely proportional to molar mass. And Among all the gases in periodic table the molar mass of Hydrogen is the least.

molar mass of H2=2 g/mol

Since, H2 has minimum molar mass then for the same mass of the gases Hydrogen will have maximum volume.

6 0

3 years ago

Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water. The molal-freezing-point-depres

yulyashka [42]

<u>Answer:</u> The freezing point of solution is -0.454°C

<u>Explanation:</u>

Depression in freezing point is defined as the difference in the freezing point of pure solution and freezing point of solution.

The equation used to calculate depression in freezing point follows:

$\Delta T_f=\text{Freezing point of pure solution}-\text{Freezing point of solution}$

To calculate the depression in freezing point, we use the equation:

$\Delta T_f=iK_fm$

Or,

$\text{Freezing point of pure solution}-\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}$

where,

Freezing point of pure solution = 0°C

i = Vant hoff factor = 2

$K_f$ = molal freezing point elevation constant = 1.86°C/m

$m_{solute}$ = Given mass of solute (KCl) = 5.0 g

$M_{solute}$ = Molar mass of solute (KCl) = 74.55 g/mol

$W_{solvent}$ = Mass of solvent (water) = 550.0 g

Putting values in above equation, we get:

$0-\text{Freezing point of solution}=2\times 1.86^oC/m\times \frac{5\times 1000}{74.55g/mol\times 550}\\\\\text{Freezing point of solution}=-0.454^oC$

Hence, the freezing point of solution is -0.454°C

3 0

3 years ago

Use wedge-bond perspective drawings (if necessary) to sketch the atom positions in a general molecule of formula (not shape clas

yuradex [85]

The atom positions in a general molecule of formula (not shape class) AXn that has shape square pyramidal at the corers of square and one at the above center of the square.

<h3>What is square pyramidal?</h3>

The square pyramidal is a shape geometry of the hybridization in which it consists of one lone pair and 5 bond pairs of electrons that repel each other and due to which the geometry changes from octahedral to square pyramidal.

As atoms are located at the four corners of the planer and one atom at the above center of the planner which is repelled by 4 atoms present at the corner of the planer.

Therefore, the atom positions in a general molecule of formula (not shape class) AXn that has a shape square pyramidal at the corners of the square and one at the above center of the square.

Learn more about square pyramidal, here;

brainly.com/question/8742529

#SPJ4

7 0

1 year ago