Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
- After 1 half-life, the mass of the element will be 32 g.
- After 2 half-lives, the mass of the element will be 16 g.
- After 3 half-lives, the mass of the element will be 8 g.
Glass is not a living organism, so it is <u>abiotic</u>.
The rows are called Periods.
Answer:
m = 4450 g
Explanation:
Given data:
Amount of heat added = 4.45 Kcal ( 4.45 kcal ×1000 cal/ 1kcal = 4450 cal)
Initial temperature = 23.0°C
Final temperature = 57.8°C
Specific heat capacity of water = 1 cal/g.°C
Mass of water in gram = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 57.8°C - 23.0°C
ΔT = 34.8°C
4450 cal = m × 1 cal/g.°C × 34.8°C
m = 4450 cal / 1 cal/g
m = 4450 g
Molar mass H₃PO₄ = 98.0 g/mol
1 mole ----- 98.0 g
? mole ------ 30.0 g
moles = 30.0 * 1 / 98.0
= 0.306 moles
hope this helps!
