Answer:
Electrons are negatively charged particles that orbits the nucleus
Explanation:
Chemical and physical properties of elements are usually determined by the number of electrons they posses. When atoms combine, they do so in order to attain stability.
When vinegar and baking soda are mixed, a new chemical called carbonic acid is made. This carbonic acid immediately decomposes into carbon dioxide gas. When you mix the vinegar and baking soda, it's the carbon dioxide gas that makes the bubbles.
Answer:
Selenium
Explanation:
Oxygen is present in the group sixteen.
This group consist of oxygen, sulfur, selenium, tellurium and polonium.
All of these have same number of valance electrons thus they show similar properties.
From the given list of elements only selenium is belong to oxygen family thus it has properties similar to the oxygen.
Electronic configuration of oxygen:
O = [He] 2s² 2p⁴
Electronic configuration of selenium:
Se = [Ar] 3d¹⁰ 4s² 4p⁴
While aluminium, boron and phosphorus are belongs to other groups that's why their properties are not similar to the phosphorus.
phosphorus is present in group 15.
Boron and aluminium are present in group 13.
Answer:
H2 and O2
Explanation:
A coffee cup calorimeter is basically a type of calorimeter that operates at constant pressure. The heat measured in the calorimeter is equal to the change in enthalpy of the reaction.
This type of calorimeter is apt for reactions involving solutions where there is little or no change in volume.
It is not generally applicable to gas phase reactions such as the reaction between H2 and O2.