Answer:
Half life = 1600 years
Explanation:
Given data:
Total mass of sample = 45.00 g
Mass remain = 5.625 g
Time period = 4800 years
Half life of radium-226 = ?
Solution:
First of all we will calculate the number of half lives passes,
At time zero 45.00 g
At first half life = 45.00 g/ 2= 22.5 g
At 2nd half life = 22.5 g/ 2 = 11.25 g
At 3rd half life = 11.25 g/ 2= 5.625 g
Half life:
Half life = Time elapsed / number of half lives
Half life = 4800 years / 3
Half life = 1600 years
Answer:
Yes , the food can be served.
Explanation:
Given the food here is served at 146°F
- According to FDA(US food and drug administration) Hot foods should be kept at an internal temperature of 140°F or warmer.
- This is the temperature recquired to maintain the bacteria without spoiling the food .
- Dishes related to eggs like quiches or soufflés should be served at a minimum of 165°F
Also given that the temperature of the food being served is 146°F which is greater than 140°F(which is the minimum value) Therefore the food can be served.
Answer:
It exerts a pressure of 3.6 atm
Explanation:
This is a gas law problem. We are looking at volume and pressure with temperature being kept constant, thus, the gas law to use is Boyle’s law. It states that at a given constant temperature, the volume of a given mass of gas is inversely proportional to the pressure of the gas.
Mathematically; P1V1 = P2V2
Let’s identify the parameters according to the question.
P1 = 1.2 atm
V1 = 375mL
P2 = ?
v2 = 125mL
We arrange the equation to make room for P2 and this can be written as:
P2 = P1V1/V2
P2 = (1.2 * 375)/125
P2 = 3.6 atm
Answer:
The correct option is D.
Explanation:
Radioactive substances usually emit different types of particles when they are decaying. Such particles include alpha particles, beta particles and gamma ray. When an alpha particle is emitted from an unstable radioactive nucleus such nucleus usually lost an atomic mass that correspond to that of helium atom. Note that an alpha particle is made up of two protons and two neutrons, which result in mass number of 4. Thus, a nucleus that emit an alpha particle will have its mass number (atomic mass) reduce by 4 and atomic number that is reduced by 2.
<span>If the aqueous solution is 34% Licl then it is 100 - 34% water = 66%
From the calculation we've found out that it is 66% water. Then we need to find the weight from a 250 g solution.
66/100 * 250 = 165g
Hence it is 165g</span>
