Isotopes are atoms of the same element that differ in the number of neutrons.
Remember that all the atoms of an element have the same number of protons. So the only difference between isotopes of an element is the number of neutrons.
86 Sr means that the mass number of this isotope is 86. Also, remember that the mass number is the number of protons plus the number of neutrons.
87 Sr means that the mass number of this isotope is 87.
So, 86 Sr and 87 Sr differ 1 neutron.
Answer: 1 neutron
1.Calcium Chloride
2.Lithium Bromide
3.Beryllium Sulfide
4.Lithium Fluoride
5. Potassium hydroselenide
6. Strontium phosphide
7.Barium Chloride
8.Iron Oxide
9.Iron
10.?
11.Copper Nitride
Answer:
So a sodium atom has the electronic configuration 2,8,1 meaning it has 1 electron on its outer shell. It has a neutral charge since the number of electrons is equal to the number of protons.
A sodium ion is one that has lost the electron on its valence shell. The electronic configuration is 2,8 and it has a positive charge because it has more protons than electrons.
Answer: m= 3.15x10-3 g NaHCO3
Explanation: To find the mass of NaHCO3 we will use the relationship between moles and molar mass. The molar mass of NaHCO3 is 84 g.
3.75x10-5 moles NaHCO3 x 84 g NaHCO3 / 1 mole NaHCO3
= 3.15x10-3 g NaHCO3
Answer:
17.83M
Explanation:
Given parameters:
Mass of KCO₂ = 1.5kg
Volume of water = 850mL
Unknown:
Molarity of solution = ?
Solution:
Molarity is defined as the number of moles per unit volume. It is the number of moles of solute in a given volume of solution.
Molarity = 
Number of moles of solute = 
Molar mass of KCO₂ = 39 + 12 + 3(16) = 99g/mol
Number of moles = 
= 15.15moles
850mL : gives 0.85L
Molarity = 
= 17.83M
