First there is a need to calculate the molar mass of Ba(NO₃)₂:
137.3 + 2 (14.0) + 6 (16) = 261.3 grams/mole
The molar mass, denoted by M in chemistry refers to a physical characteristic illustrated as the mass of a given component divided by the amount of the component. The molar masses are always denoted in grams/mole.
After finding the molar mass, the number of moles can be identified as:
432 grams / 261.3 g/mol = 1.65 moles of Ba(NO₃)₂.
Answer:
320 g
Step-by-step explanation:
The half-life of Co-63 (5.3 yr) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
half-lives t/yr Remaining Remaining/g
0 0 1
1 5.3 ½
2 10.6 ¼
3 15.9 ⅛ 40.0
4 21.2 ¹/₁₆
We see that 40.0 g remain after three half-lives.
This is one-eighth of the original mass.
The mass of the original sample was 8 × 40 g = 320 g
I have a feeling that #2 is the one.
You have to start listing from the bottom :
3. Secondary Consumers
2. Primary Consumers
1. Producer
Answer:
Atoms
Explanation:
Elements are the chemical combinations of two or more atoms of the same kind
