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2 years ago

What is the rule for determining the mass of an atom

Chemistry

1 answer:

Elena-2011 [213]2 years ago

5 0

Answer:

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit. By adding together the number of protons and neutrons and multiplying by 1, you can calculate the mass of the atom.

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What’s a giant hunk of rock and metal

Aleksandr-060686 [28]

Answer: “We live on a hunk of rock and metal that circles a humdrum star that is one of 400 billion other stars that make up the Milky Way Galaxy which is one of billions of other galaxies which make up a universe which may be one of a very large number, perhaps an infinite number, of other universes. That is a perspective on human life and our culture that is well worth pondering.”

― Carl Saga

Is this it mate?

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3 years ago

Groups or families in the periodic table have what in common

sammy [17]

Each column is called a group<span>. The elements in each </span>group have<span> the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons.</span>

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2 years ago

Read 2 more answers

A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 8.10kg of water at 33.9 degree

lions [1.4K]

Answer:

The new temperature of the water bath 32.0°C.

Explanation:

Mass of water in water bath ,m= 8.10 kg = 8100 g ( 1kg = 1000g)

Initial temperature of the water = $T_1=33.9^oC=33.9+273K=306.9 K$

Final temperature of the water = $T_2$

Specific heat capacity of water under these conditions = c = 4.18 J/gK

Amount of energy lost by water = -Q = -69.0 kJ = -69.0 × 1000 J

( 1kJ=1000 J)

$Q=m\times c\times \Delta T=m\times c\times (T_2-T_1)$

$-69.0\times 1000 J=8100 g\times 4.18 J/g K\times (T_2-306.9 K)$

$-69,000.0 J=8100 g\times 4.18 J/g K\times (T_2-306.9 K)$

$T_2=304.86 K=304.86 -273^oC=31.86^oC\approx 32.0^oC$

The new temperature of the water bath 32.0°C.

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3 years ago

Xenon forms several compounds with oxygen and fluorine. It is the most reactive non-radioactive noble gas because a. its large r

muminat

Answer:

d. its effective nuclear charge is lower than the other noble gases.

Explanation:

Xenon belongs to group O on the periodic table. Most of the elements here are unreactive.

Due to the large size of Xenon, the outermost electrons have very low effective nuclear charge. Effective nuclear charge is the effect of the positive charges of the nucleus on the electrons in orbits. This effect decreases outward as atomic shell increases.

Xenon has a very large atomic radius and there is weak a nuclear charge on the outermost electrons. The more electronegative elements would be able to attract some of its outermost electrons easily and form chemical bonds with xenon much more readily.

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3 years ago

11C. Potassium hydrogen phthalate is a solid, monoprotic acid frequently used in the laboratory to standardize strong base solut

Llana [10]

For the reactants,

The oxidation number of hydrogen = +1
The oxidation number of oxygen = -2
The oxidation number of arsenic = +5
The oxidation number of carbon = +3

For the products,

The oxidation number of hydrogen = +1
The oxidation number of oxygen = -2
The oxidation number of arsenic = +3
The oxidation number of carbon = +4

Here, arsenic (+5 to +3) and carbon (+3 to +4) are the only oxidation numbers changing.

Note that an increase in oxidation number means electrons are lost. Thus oxidation is occurring, and a decrease in oxidation number means electrons are being gained, and thus reduction is occurring.

Also, the compound that contains the element being oxidized is the reducing agent, and the compound that contains the element being reduced is the oxidizing agent.

So, the answers are:

name of the element oxidized: Carbon

name of the element reduced: Arsenic

formula of the oxidizing agent: $\text{H}_{3}\text{AsO}_{4}$

formula of the reducing agent: $\text{H}_{2}\text{C}_{2}\text{O}_{4}$

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1 year ago