3 years ago

An atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom

Chemistry

1 answer:

AlladinOne [14]3 years ago

5 0

Answer:

Atomic mass =70

Explanation:

Mass number is total protons +total neutrons

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Carbon exists in nature as three isotopes. Given the atomic masses and relative abundance of the isotopes, what is the average a

Ivan

The most abundant carbon isotope is carbon-12.

The relative atomic mass of carbon is 12.011, which is extremely close to 12.0. This means that the masses C-13, and C-14 are practically negligible when contributing to the relative atomic mass of carbon.

the C-12 isotope makes up 98.9% of carbon atoms, C-13 makes up 1.1% of carbon atoms, and C-14 makes up just a trace of carbon atoms as they are found in nature.

6 0

2 years ago

1. Why were atoms given the name of "atom" which means "unable to be cut?"

alexandr1967 [171]

Answer:

These particles were considered so small that they were unable to be cut

3 0

3 years ago

15.0 mL of an unknown clear liquid is added to a 50 mL graduated cylinder. The mass of the liquid is determined to be 12.7 grams

sveticcg [70]

Answer:

$\boxed {\tt A. \ d=0.85 \ g/mL}$

Explanation:

Density is found by dividing the mass by the volume.

$d=\frac{m}{v}$

The mass of the liquid is 12.7 grams.

We know that 15 mL of this liquid was added to a 50 mL graduated cylinder. Therefore, the volume is 15 mL. The 50 mL is not relevant, it only tells us about the graduated cylinder.

$m= 12.7 \ g\\v= 15 \ mL$