Answer:
Mendeleev had left the noble gases out of his periodic table.
Explanation:
Mendeleev's periodic table is pictured in the image attached to the question.
Mendeleev's table obviously lacked the noble gases. The reason for this grave omission is simple; the noble gases were not known as at the time when he formulated his periodic table. There weren't any known elements whose properties were similar to the properties of the noble gases. This would have lead him to suspect their existence.
Answer:
2Mg + O₂ → 2MgO
Explanation:
Chemical equation:
Mg + O₂ → MgO
Balanced chemical equation:
2Mg + O₂ → 2MgO
The balanced equation s given above and it completely follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Steps to balanced the equation:
Step 1:
Mg + O₂ → MgO
Mg = 1 Mg = 1
O = 2 O = 1
Step 2:
2Mg + O₂ → MgO
Mg = 2 Mg = 1
O = 2 O = 1
Step 3:
2Mg + O₂ → 2MgO
Mg = 2 Mg = 2
O = 2 O = 2
they all have one thing in common and that its all made up of atoms. When these components are active it creates energy
Answer:
DNA consists of molecules called nucleotides. Each nucleotide comprises a group of phosphates, a group of sugars and a base of nitrogen. The four forms of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The sequence of these bases defines the DNA instructions or genetic code.
<u>Answer</u>:
The inner walls of a vacuum flask have a silver coating to reduce heat loss by radiation.
<u>Explanation</u>:
The vacuum flask has an inner silver lining to prevent the transfer of heat by radiation. Radiation is a process where the emission or transformation of energy happens in the form of wave or the particles through the material medium.
Vacuum flask being working as thermal insulator helps in maintaining the substance its actual temperature for a long time. The silver lining acts as a reflector .It prevents the heat radiation to released out of the flask.
