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3 years ago

An atom is

Chemistry

2 answers:

34kurt3 years ago

8 0

The answer is a. the smallest unit of matter that maintains its chemical identity.

Dennis_Churaev [7]3 years ago

3 0

Answer:

a. the smallest unit of matter that maintains its chemical identity.

Explanation:

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How does heat conduction work in the metal brownie pan?

34kurt

The metal conducts the heat and through conduction, cooks the brownies; conduction also cooks the brownies in the glass pan, but since infrared goes right through the glass, they also cook by radiation.

7 0

3 years ago

We gave an object with a density of 620 g/cm^3 and a volume of 75cm^3. What is the mass of this object?

Hitman42 [59]

$d=\frac{m}{V} \ \ \ \Rightarrow \ \ m=dV\\\\
d=620\frac{g}{cm^{3}}\\
V=75cm^{3}\\\\\
m=620\frac{g}{cm^{3}}*75cm^{3}=46500g$

6 0

3 years ago

Give the number of lone pairs around the central atom and the molecular geometry of XeF4.A)0 lone pairs, tetrahedralB)1 lone pai

vovangra [49]

Answer: 2 lone pairs, square planar

Explanation:

Using the VSEPR ( Valence Shell Electron Pair Repulsion)Theory

To calculate the number of lone pairs electron can be done using the formula;

Number of electrons = ½ (V+N-C+A)

V mean valency of the central atom

N means number of monovalent bonding atoms

C means charge on cation

A means charges on anion

Therefore, to calculate the number of lone pair electron C=A=0;

Number of electrons = ½ (8+4) = 12/2 = 6

Number of bonding pair = 4

Number of lone pairs of electron = 6-4 = 2

The hybridrization of the compound is sp3d2 because the number of electrons around the central atom is 6.

The geometry of the compound is square planar and this is because of the repulsion between the bonding pair of electrons and lone pair of electrons which causes the lone pair of electrons to lie in a perpendicular plane in order to acquire stability.

4 0

3 years ago

1.5mol C3H8 from C3H8+5O2-->3CO2+4H2O .how many grams of carbon dioxide are produced

koban [17]

Answer:

$\large \boxed{\text{200 g CO}_{{2}}}$

Explanation:

We will need a balanced equation with masses, moles, and molar masses, so let’s gather all the information in one place.

Mᵣ: 44.01

C₃H₈ + 5O₂ ⟶ 3CO₂ + 4H₂O

n/mol: 1.5

1. Calculate the moles of CO₂

The molar ratio is 3 mol CO₂:1 mol C₃H₈

$\rm \text{Moles of CO}_{2} = \text{1.5 mol C$_{3}$H}_{8} \times \dfrac{\text{3 mol CO}_{2}}{\text{1 mol C$_{3}$H}_{8}} =\text{4.5 mol CO}_{2}$

2. Calculate the mass of CO₂.

$\text{Mass of CO}_{2} = \text{4.5 mol CO}_{2} \times \dfrac{\text{44.01 g CO}_{2}}{\text{1 mol CO$_{2}$}} = \textbf{200 g CO}_{\mathbf{2}}\\\text{The reaction will form $\large \boxed{\textbf{200 g CO}_{\mathbf{2}}}$}$

3 0

3 years ago

6.0 g of copper was heated from 20 degree c to 90 degree c . How much energy was used to heat cu?

Darina [25.2K]

Copper heat capacity would be <span>0.385J/C*gram which means it needs 0.385 Joule of energy to increase 1 gram of copper temperature by 1 Celcius. The calculation would be:
energy= heat capacity *mass * temperature difference
energy= </span>0.385J/C*gram * 6g * (90-20)
<span>energy= 161.7J
</span>

4 0

3 years ago