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3 years ago

Given that oxygen has an atomic number of 8.

Chemistry

2 answers:

Tcecarenko [31]3 years ago

7 0

Answer:

Oxygen (O), for example, has three naturally occurring isotopes, which can be written as 8/16O, 8/17 O, and 8/18O.

Explanation:

professor190 [17]3 years ago

4 0

Answer: 8 protons and 10 neutrons

Explanation:

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

atomic number = 8 = Number of protons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

Mass number = 18 = Number of protons + Number of neutrons

Thus Number of neutrons =18 - Number of protons= 18 - 8 = 10

Thus there are 8 protons and 10 neutrons in Oxygen -18.

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If 45.6 grams of water decompose at 301 Kelvin and 1.24 atmospheres, how many liters of oxygen gas can be produced? Show all of

Artyom0805 [142]

This reaction is called the electrolysis of water. The balanced reaction is:

2H2O = 2H2 + O2

<span>
We are given the amount of water for the electrolysis reaction. This will be the starting point of our calculation.

45.6 grams H2O (1 mol H2O / 18.02 g H2O) (1 mol O2 / 2 mol H2O) = 1.27 mol O2

V = nRT/P = </span><span>1.27 mol O2 (0.08206 atm L / mol K) (301 K) / 1.24 atm
V = 25.20 L O2</span>

6 0

3 years ago

Plz help. I just need someone to check answer. :(

My name is Ann [436]

These substances can be separated by distillation, so your answer is A.

5 0

3 years ago

"A crosslinked copolymer consists of 57 wt% ethylene (C2H4) repeat units and 43 wt% propylene (C3H6) repeat units. Determine the

ch4aika [34]

Explanation:

Percentage ethylene by weight = 57%

Percentage propylene by weight = 43%

Suppose in 100 grams of polymer:

Mass of ethylene = 57 g

Mass of propylene = 43 g

Moles of ethylene = $\frac{57 g}{28 g/mol}=2.036 mol$

Moles of propylene = $\frac{43g}{42g/mol}=1.024 mol$

1 mole = $N_A =6.022\times 10^{23}$ molecules/ atoms

Units of ethylene = $2.036 mol\times N_A$

Units of propylene = $1.024 mol\times N_A$

a) Fraction of ethylene units:

$=\frac{2.036 mol\times N_A}{2.306 mol\times N_A+1.024 mol\times N_A}=\frac{509}{765}$

b ) Fraction of propylene units:

$=\frac{1.024mol\times N_A}{2.306 mol\times N_A+1.024 mol\times N_A}=\frac{256}{765}$

3 0

3 years ago

The specific heat of wood is 2.03 J/g.°C. How much

Brilliant_brown [7]

Answer:

11419 J/g/ 11.419 KJ/g

Explanation:

H=MCQ

H=225×2.03×(-15-10)

H=225×2.03(25) Note; negative sign is of no use

H=11419J/g

3 0

3 years ago

A student is determining the density of an unknown metal with a mass of 32.56 g. The student partially fills a graduated cylinde

xenn [34]

Answer:

The metal is Tin (Sn)

Explanation:

The following data were obtained from the question:

Mass of metal = 32.56 g

Volume of water = 14.78 mL

Volume of water + metal = 20.44 mL

Next, we shall determine the volume of the metal. This is illustrated below:

Volume of water = 14.78 mL

Volume of water + metal = 20.44 mL

Volume of metal =..?

Volume of metal = (Volume of water + metal) – (Volume of water )

Volume of metal = 20.44 – 14.78

Volume of metal = 5.66mL

Next, we shall determine the density of the metal.

Density of a substance is defined as the mass of the substance per unit volume of the substance. Mathematically, the density of a substance is expressed as:

Density = Mass / volume

With the above formula, we can obtain the density of the metal as follow:

Mass of metal = 32.56 g

Volume of metal = 5.66mL

Density =.?

Density = Mass /volume

Density = 32.56g/5.66mL

Density of the metal = 5.75g/mL

Comparing the density of the metal with standard density of elements, the metal is Tin (Sn)

4 0

3 years ago