Question

1. at stp, a 7.49 - gram sample of an element has a volume of 1.65 cubic centimeters. the sample is most likely
2. ta
3. tc
4. te
5. ti
6. as the elements in group 15 are considered in order of increasing atomic number, which sequence in properties occurs?
7. metalloid → metal → nonmetal
8. metal → metalloid → nonmetal
9. nonmetal → metalloid → metal
10. metal → nonmetal → metalloid

Explanation:

Question 18

Step1: Calculate the density

Density formula: $
ho=\frac{m}{V}$. Given $m = 7.49\ g$ and $V=1.65\ cm^{3}$.
$
ho=\frac{7.49\ g}{1.65\ cm^{3}}\approx4.54\ g/cm^{3}$

Step2: Recall the density of elements

• Tantalum (Ta) has a density of about $16.65\ g/cm^{3}$
• Technetium (Tc) has a density of about $11.5\ g/cm^{3}$
• Tellurium (Te) has a density of about $6.24\ g/cm^{3}$
• Titanium (Ti) has a density of about $4.5\ g/cm^{3}$

Group 15 elements (Nitrogen - N, Phosphorus - P, Arsenic - As, Antimony - Sb, Bismuth - Bi). Nitrogen and Phosphorus are non - metals. Arsenic is a metalloid. Antimony is a metalloid (some sources consider it a metal - like metalloid). Bismuth is a metal. As atomic number increases (N(7) < P(15) < As(33) < Sb(51) < Bi(83)), the trend is nonmetal → metalloid → metal.

Answer:

1. Ti

Question 19