Answer:
Carbon-13
Explanation:
Carbon have three isotopes. Isotopes are the atoms of the same element which has a different number of neutrons. Carbon has 3 isotopes.
Carbon-12 : 6 electrons I 6 protons I 6 neutrons
Carbon-13 : 6 electrons I 6 protons I 7 neutrons
Carbon-14 : 6 electrons I 6 protons I 8 neutrons
Answer:
Explanation:
When you are in the laboratory and take a direct sniff of the chemicals you are using, you run the risk of damaging your mucous membranes or your lungs. When it is necessary to smell chemicals in the lab, the proper technique is to cup your hand above the container and waft the air toward your face.
The atomic mass of Europium is 152 amu
Work:
151(0.4803) = 72.52 amu
153(0.5197) = 79.5 amu
72.5 + 79.5 = 152 amu
Answer:
1. filtration and evaporation
2. i) water is added to the sand and salt mixture
ii) then the mixture is filtrated and so the sand and the salt water was seperated
iii) the salt water is heated with the help of burner until the water gets evaporated
iv) after the water gets evaporated, the salt is remained in the container
3. observation:
- on adding water to the mixture, the salt is completely dissolved in the water
- when filtrated the sand is seperated from the salt water
- now the salt water when heated with the burner until the evaporation, the water is evaporated
- the salt is precipitated and remained in the container
4. cautions:
- while using the burner, we should be cautious with fire
- the container that is heated should be holded with the help of a cloth to avoid heat
