The instrument that measures air pressure is called a barometer. It measures the wind pressure and it is easy to move and read.
Hope I helped!
- Amber
Answer:
Option D (
)
Explanation:
Acids react with metal to form salt and hydrogen gas.
Metals which are more reactive than hydrogen evolve hydrogen gas on reaction with acid.
For example:
Magnesium reacts with hydrogen chloride to form magnesium chloride and hydrogen.
2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)
Al and Zn are more reactive than hydrogen, therefore, these metals evolve hydrogen gas on reaction with acid.
reacts with HCl to form NaCl and nitric oxide.
reacts with HCl to form potassium chloride, carbon dioxide and water.
As reaction of does not evolve any gas, therefore, the correct option is D.
density of acetone in gm/cm^3 is 0.791
=28.80cm^3*0.791 g/cm63
=22.78 g
Answer:
Explanation:
Here, a balance between attraction between nucleus and electrons, and electron-electron, and nuclei-nuclei repulsion play role.
All chemical bonds are formed by overlapping of orbitals. If the electronegativity of the two elements forming the bond is very different (elements from the 1st ,2nd groups with elements of 7th group) then ionic bond are formed. If the electronegativities are more similar, then overlapping is stronger, and covalent bonds are formed.
Answer:
Demonstration 1 showed a chemical change because a new gaseous substance was formed, and demonstration 2 showed a physical change because liquid water became water vapor.
Explanation:
Chemical changes alter the chemical makeup of a subject, and a physical change only alters the appearance of a subject, not the chemical makeup.
