Answer:
To find the number of moles we must first calculate the molar mass( M) of Fe2O3
Molar mass = mass / number of moles
M(Fe2O3) = (55.8 ×2) + (16×3)
= 111.6 + 48
= 159.6 g/mol
number of moles = mass / molar mass
= 125g/159.6g/mol
= 0.783mol
Hope this helps
6.
7. 6 × 7 = 42
42 ÷ 10 = 4,2 Pizzas
You need to buy 4 or 5 Pizzas.
Answer: There are 7 alpha-particle emissions and 4 beta-particle emissions involved in this series
Explanation:
Alpha Decay: In this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. The mass number is reduced by 4 units and atomic number is reduced by 2 units.
Beta Decay : It is a type of decay process, in which a proton gets converted to neutron and an electron. This is also known as -decay. In this the mass number remains same but the atomic number is increased by 1.
In radioactive decay the sum of atomic number or mass number of reactants must be equal to the sum of atomic number or mass number of products .
Thus for mass number : 235 = 207+4X
4X= 28
X = 7
Thus for atomic number : 92 = 82+2X-Y
2X- Y = 10
2(7) - Y= 10
14-10 = Y
Y= 4
Thus there are 7 alpha-particle emissions and 4 beta-particle emissions involved in this series
Answer:
Physical change is the change that you can see like for example if you turn your light on and off thats physical (thats the best definition for that i can do) and also physical change can go back to its original form it was before. A chemical change is when you do something to something and it cannot be changed back to its original form. Like for example, if you bake a pie, you cannot un-cook all the ingredients to make it raw again
Explanation:
learned this in 5th grade
Answer: TWO.
At least two groups: treatment group and control group.
The treatment group is that is exposed to the different levels of the independent variable ( a medication for example), while the control group is not treated, so the researchers can compare the effect of the medication.