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2 years ago

What is an atom in chemistry

Chemistry

2 answers:

tamaranim1 [39]2 years ago

8 0

And atom is the smallest unit of matter

oksano4ka [1.4K]2 years ago

6 0

Answer:

Explanation:

An atom is the smallest unit of matter that has the properties of an element. It is composed of a dense core called the nucleus and a series of outer shells occupied by orbiting electrons.

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Problem 4

Hunter-Best [27]

<h3>Answer:</h3>

1.93 g

<h3>Explanation:</h3>

<u>We are given;</u>

The chemical equation;

2C₂H₆(g) + 7O₂(g) → 4CO₂(g) + 6H₂O(l) ΔH = -3120 kJ

We are required to calculate the mass of ethane that would produce 100 kJ of heat.

From the equation given;

2 moles of ethane burns to produce 3120 Kilo joules of heat

Therefore;

Number of moles that will produce 100 kJ will be;

= (2 × 100 kJ) ÷ 3120 kJ)

= 0.0641 moles

But, molar mass of ethane is 30.07 g/mol

Therefore;

Mass of ethane = 0.0641 moles × 30.07 g/mol

= 1.927 g

= 1.93 g

Thus, the mass of ethane that would produce 100 kJ of heat is 1.93 g

3 0

3 years ago

What is the Molar Mass of methylammonium bromide: Use the Periodic Table and round to the nearest hundredths.

egoroff_w [7]

The molar mass of methylammonium bromide is 111u.

<h3>What is molar mass?</h3>

The molar mass is defined as the mass per unit amount of substance of a given chemical entity.

Multiply the atomic weight (from the periodic table) of each element by the number of atoms of that element present in the compound.

Add it all together and put units of grams/mole after the number.

Atomic weight of H is 1u

Atomic weight of N is 14u

Atomic weight of C is 12u

Atomic weight of Br is 79u

Calculating molar mass of $2H_3NCH_3Br$ =2(1 x3+ 14+12+ 1 x 3 +79) = 111u

Hence, the molar mass of methylammonium bromide is 111u.

Learn more about molar mass here:

brainly.com/question/12127540

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8 0

1 year ago

The half life of oxygen is 2 minutes. What fraction of a sample of 0.15 will remain after 5 half lives?

Natasha_Volkova [10]

Answer:

3.13%.

Explanation:

The following data were obtained from the question:

Original amount (N₀) = 0.15

Half life (t½) = 2 mins

Number of half-life (n) = 5

Fraction of sample remaining =.?

Next, we shall determine the amount remaining (N) after 5 half-life. This can be obtained as follow:

Amount remaining (N) = 1/2ⁿ × original amount (N₀)

NOTE: n is the number of half-life.

N = 1/2ⁿ × N₀

N = 1/2⁵ × 0.15

N = 1/32 × 0.15

N = 0.15/32

N = 4.69×10¯³

Therefore, 4.69×10¯³ is remaining after 5 half-life.

Finally, we shall the fraction of the sample remaining after 5 half-life as follow:

Original amount (N₀) = 0.15

Amount remaining (N) = 4.69×10¯³

Fraction remaining = N/N₀ × 100

Fraction remaining = 4.69×10¯³/0.15 × 100

Fraction remaining = 3.13%

3 0

2 years ago

Write in scientific form<br> 0.00580 → <br><br> 3000 → <br><br> 0.000908 → <br><br> 200. →

vagabundo [1.1K]

Answer:

Explanation:

0.00580=5.8*10^-3

3000=3.0*10^3

0.000908=9.08*10^-4

200.=2.0*10^2

6 0

2 years ago

1. Based on the observed performance of the air bag models and the amounts of sodium bicarbonate and acetic acid (vinegar) neede

Ira Lisetskai [31]

Sodium bicarbonate and acetic acid are not good substitute for sodium azide in airbags since the require more mass and produce less gas.

<h3>Which is the better chemical for an airbag?</h3>

The chemical equation for the production of nitrogen gas from sodium azide is given below:

NaN₃ → 2 Na + 3 N₂

1 mole or 66 go of sodium azide produces 3 moles or 67.2 L of nitrogen gas.

The equation for the production of carbon dioxide from sodium bicarbonate and acetic acid is given below:

Na₂CO₃ + CH₃COOH → CH₃COONa + CO₂ + H₂O

1 mole, 106 g of Na₂CO₃ and 1 mole, 82 g of CH₃COOH are required to produce 1 mole or 22.4 L of CO₂.

The mass of sodium azide required is less than that of sodium bicarbonate and acetic acid required. Also, sodium azide produces a greater volume of gas. Therefore, sodium bicarbonate and acetic acid are not good substitute for sodium azide in airbags.

In conclusion, sodium azide is a better choice in airbags.

Learn more about airbags at: brainly.com/question/14954949

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7 0

1 year ago

What is an atom in chemistry​

What is an atom in chemistry