We can define atomic mass the total of number of protons and number of neutrons in an atom or isotope.
<span>So when an isotope of yttrium has 39 protons and 59 neutrons, its atomic mass is equal to;
number of protons + number of neutrons = 39 + 59 = 98</span>

8 0

3 years ago

PLSSSS HELP<br> this is science

jenyasd209 [6]

Answer:

<h2>The answer is C </h2>

Explanation:

when a car begins to slow down the speed that it was going will decrease. Which means that it is an example of deceleration.

4 0

3 years ago

Read 2 more answers

The boiling points for the homonuclear diatomic molecules in the halogen family are 85 K, 238 K, 332 K, 457 K and 610 K. Which s

patriot [66]

Answer:

$Cl_{2}$ has boiling point of 238 K

Explanation:

Boiling point depends on different intermolecular force such as molecular wight, dipole-dipole attraction force, hydrogen bonding, ionic attraction force.

Homonuclear diatomic molecules are covalent non-polar molecules and thereby free from dipole-dipole attraction force, hydrogen bonding and ionic interaction forces.

Hence, boiling point of homonuclear diatomic molecules depends solely on molecular weight.

We know, higher the molecular weight of a molecule, higher will be its boiling point. This phenomenon can be realized in terms of increasing london dispersion force with increase in molecular weight.

Decreasing order of molecular weight of halogen molecules :

$I_{2}$ > $Br_{2}$ > $Cl_{2}$ > $F_{2}$

So, decresing order of boiling point of halogen molecules:

$I_{2}$ > $Br_{2}$ > $Cl_{2}$ > $F_{2}$

Hence $Cl_{2}$ has boiling point of 238 K

4 0

3 years ago

Why metals are denser than non - metals ? ...?

Solnce55 [7]

Because their molecules are more tightly packed. Massdensity = ---------- Volume
So more densely packed molecules means more mass per unit volume. Hence metals are denser than non-metals.

6 0

3 years ago