True because if an old theory finds new information that can be changed if it’s different then the original material
The atomic mass of an element is the number of times of an atom of that element is heavier than an atom of carbon taken as 12. In simpler way, atomic mass is number of protons present in nucleus of an atom, which is a characteristic of an chemical element and is determines place of the element in the periodic table. Mass number is total number of protons and neutrons. If an uncharged atom looses electron from its outermost shell, it becomes cation, which is positively charged species. Atomic number and mass number do not change if electron goes out of an atom.
Uncharged copper after loosing two electrons is converted to 
which can be represented as follows:
→
The half-life of carbon-14 is about 5730 years
Answer:
Option D. 3, 1, 3, 1
Explanation:
From the question given above,
HNO₃ + Al(OH)₃ —> HOH + Al(NO₃)₃
The equation can be balance as follow:
HNO₃ + Al(OH)₃ —> HOH + Al(NO₃)₃
There are 3 atoms of N on the right side and 1 atom on the left side. It can be balance by 3 in front of HNO₃ as shown below:
3HNO₃ + Al(OH)₃ —> HOH + Al(NO₃)₃
There are a total of 6 atoms of H on the left side and 2 atoms on the right side. It can be balance by 3 in front of HOH as shown below:
3HNO₃ + Al(OH)₃ —> 3HOH + Al(NO₃)₃
Now, the equation is balanced.
Thus, the coefficients are 3, 1, 3, 1
Moles of NaN3 at STP = volume of gas / 22.4 = 11.5/22.4 = 0.5mole. Massof NaN3 = moles of NaN3 x molecular weight = 0.5 x 65 = 32.5 grams.
