Answer:
must have the same number of protons
Answer:
m= 4,599.145 g
Explanation:
Let m = mass, d = density and V = volume of the osmium block.
m = d x V
m = 22.610 g/cm3 x (6.70 x 9.20 x 3.3) cm3
m = 4,599.145 g
Answer:
1.125
Explanation:
I think it is his because if you add 0.30 and 0.15 it adds up to 0.45 so you just multiply 0.45 and 2.5 and then it gives you 1.125. HOPE IT HELPS.
9.0 grams will produce 11 L of hydrogen
The symbol : 
<h3>Further explanation
</h3>
There are two components that accompany an element, the mass number and atomic number
Atoms are composed of 3 types of basic particles (subatomic particles): <em>protons, electrons, and neutrons
</em>
The Atomic Number (Z) indicates the number of protons and electrons in an atom of an element.
Atomic number = number of protons = number of electrons ⇒ neutral number
Atomic mass is the sum of protons and neutrons
Atomic Number (Z) = Atomic mass (A) - Number of Neutrons
The element has 71 electrons and a charge of +1 , so
Number of protons = 71 + 1 = 72
Number of protons = the atomic number = 72
The element with atomic number 72 is Hafnium(Hf)
The atomic mass of Hf = 178 g/mol