Atomic Structure
How many neutrons are in 146C?
8
The size of metal atoms
A) generally increases progressively from top to bottom in a group in the periodic table.
B) generally increases progressively from left to right in a period.
C) are smaller than those of the corresponding ions.
D) do not change upon losing electrons.
A) generally increases progressively from top to bottom in a group in the periodic table.
Give the name for FeBr3
Iron (III) Bromide
The limiting reagent for a given reaction can be recognized because it is the reagent that
A) has the smallest coefficient in the balanced equation for the reaction.
B) has the smallest mass in the reaction mixture.
C) is present in the smallest molar quantity.
D) would be used up first.
D) would be used up first
How many covalent bonds are represented in the formula NH4Cl?
Which statement is true?
A) The nucleus of an atom contains neutrons and electrons.
B) The atomic number of an element is the number of protons in the nucleus plus the number of electrons.
C) The mass number of an atom is the number of protons in the nucleus plus the number of electrons outside.
D) The number of electrons outside the nucleus is the same as the number of neutrons in the nucleus.
B) The atomic number of an element is the number of protons in the nucleus plus the number of electrons.
Which of these elements has the smallest atomic radius?
A) fluorine
B) chlorine
C) bromine
D) iodine
A) fluorine
How many moles of hydrogen atoms are in six moles of Ca(OH)2?
12
What are the smallest whole number coefficients for each substance (respectively) in the chemical reaction when balanced?
_NaBr + _Cl2 --> _NaCl + _Br2
A) 1,1,2,2
B) 1,2,2,2
C) 2,1,2,1
D) 2,4,2,4
Which molecule contains carbon with a negative formal charge?
A) CO
B) CO2
C) H2CO
D) CH4
A) CO
Which atom has the most neutrons?
A) neon-20
B) Chlorine-35
C) Phosphorous-32
D) Sulfur-35
D
Which species has this ground-state electron arrangement?
1s22s22p63s23p63d10
Zn2+
If gallium, atomic number 31, combines with selenium, atomic number 34, what is the most likely formula based on your knowledge of the periodic nature of the elements?
Ga2Se3
How many moles of water are necessary to react completely with 8.0 mol PCl5?
PCl5 + 4H2O --> H3PO4 + 5HCl
32 moles
A central atom has two lone pairs and three single bonds. What is the molecular geometry?
T-shaped
Lithium has two naturally occurring isotopes, 6Li and 7Li, with masses of 6.015 amu and 7.016 amu, respectively. What is the relative abundance of each isotope?
6Li = 7.49% and 7Li = 92.51%
What is the energy of a photon with a wavelength of 656 nm?
3.03 x 10-19 J
A molecular compound is found to consist of 30.4% nitrogen and 69.6% oxygen. If the molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule?
92 g/mol
What amount of Al2O3 is produced from the reaction of 3.0 mol Al with 2.0 mol Fe2O3?
2Al + Fe2O3 --> Al2O3 + 2Fe
1.5 mole
Which molecule has 1200 bond angles?
A) CO2
B) NH3
C) IF3
D) SO3
D) SO3
Bromine has two naturally occurring isotopes. The most abundant isotope (50.69%) is 7935Br of mass 78.9183 amu. What is the other isotope?
8135Br
When excited, a sodium ion emits a photon of frequency 5.09 x 1014 s-1. What is the energy associated with this emission?
3.37 x 10-19 J
A 3.41 x 10-6 g sample is known to contain 4.67 x 1016 molecules. What is this compound?
A) CH4
B) CO2
C) H2O
D) NH3
B) CO2
What amount of the excess reagent remains when 0.500 mol Li reacts with 0.350 mol N2?
6Li (s) + N2 (g) --> 2Li3N (s)
0.267 mol N2
How many sigma and pi bonds are in C6H6?
12 sigma and 3 pi