Answer:
Nitrogen
Explanation:
Nitrogen has 5 Valence Electrons.
And its atomic mass is also less than Bismuth.
There are other elements in the 5th row but this one has the lowest atomic mass compared to the others.
Answer:

Explanation:
We are given a number of particles and asked to convert to moles.
<h3>1. Convert Particles to Moles </h3>
1 mole of any substance contains the same number of particles (atoms, molecules, formula units) : 6.022 *10²³ or Avogadro's Number. For this question, the particles are not specified.
So, we know that 1 mole of this substance contains 6.022 *10²³ particles. Let's set up a ratio.

We are converting 2.98*10²³ particles to moles, so we multiply the ratio by that value.

The units of particles cancel.



<h3>2. Round</h3>
The original measurement of particles (2.98*10²³) has 3 significant figures, so our answer must have the same.
For the number we found, 3 sig figs is the thousandth place.
The 8 in the ten-thousandth place (0.4948522086) tells us to round the 4 up to a 5 in the thousandth place.

2.98*10²³ particles are equal to approximately <u>0.495 moles.</u>
Answer:
Ratios in order of increasing value ; The ratio of the mass ratio of Y to X in XY2 to the mass ratio of Y to X in XY, The ratio of the mass ratio of Y to X in XY3 to the mass ratio of Y to X in XY, The ratio of the mass ratio of Y to X in XY4 to the mass ratio of Y to X in XY
1) Mass ratio = 3
2) Mass ratio = 2
3) Mass ratio = 4
Explanation:
The detailed and step by step calculation is shown in the attachment.
Answer:
Tantalium is a Transition metal.
Osmium is a Transition metal.
Thorium is radioactive Metal.