Doing some homework, are my answers right?

HCN= Polar
HCOOH= Polar
H2CCCH2= Nonpolar

Out of the following elements: Na, H, and Au order them least to greatest in the following:

Eletronegativity= Na is smallest, H is second, Au is largest

Ionization Energy= Na is smallest, Au is second, H is largest

Atomic Radius= H is smallest, Au is second, Na is largest.

Thanks for checking, please tell me if I got any wrong!

See this table for ionization energy.

http://www.lenntech.com/periodic-chart-elements/ionization-energy.htm

Let's check your answers!

For the first part:
HCN is a polar molecule because it has a lone pair of electrons on the nitrogen atom that creates an uneven distribution of charge.
HCOOH is also a polar molecule because the oxygen atom pulls electron density towards itself, leading to an unequal distribution of charge.
H2CCCH2 is a nonpolar molecule because it is symmetrical, meaning it has a balanced distribution of charge and no net dipole moment. Therefore, you are correct in classifying it as nonpolar.

Now, let's move on to the second part:

For electronegativity:
You are correct that Na is the smallest electronegativity, H is next, and Au has the largest electronegativity.

For ionization energy:
Ionization energy refers to the energy required to remove an electron from an atom or ion. In this case:
Na has the smallest ionization energy because it has relatively low electron affinity and a tendency to lose its outer electron easily.
Au has the second highest ionization energy because it is less likely to lose its outer electron compared to Na.
H has the largest ionization energy because it has a high electron affinity and a strong attraction to its only electron.

For atomic radius:
The atomic radius refers to the size of the atom. In this case:
H has the smallest atomic radius because it is the smallest atom among Na, H, and Au.
Au has the second largest atomic radius because it is larger than H but smaller than Na.
Na has the largest atomic radius because it is the largest atom among the three.

Based on your explanations, your answers appear to be correct. Well done!

Your answers are correct. Well done!