Answer: metal and carbonate
Explanation:
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions
when dissolved in water and an acid is defined as a substance which donates hydrogen ions
in water.
An acid is represented as :

1. When metal is treated with an acid such as
, if the metal is more reactive than hydrogen displaces hydrogen from its salt solution and thus produce zinc chloride and hydrogen gas.
2. When carbonates are treated with acid, double displacement takes place ad carbon dioxide is released as a gas.

<span>NH4NO2(s)---> N2(g) + 2H2O(l)</span>
Answer:
C) mass.
Explanation:
The speed of a body is given by the relation between the displacement of a body in a given time. It can be considered the greatness that measures how fast a body moves.
Speed analysis is divided into two main topics: average speed and instantaneous speed. It is considered a vector quantity, that is, it has a module (numerical value), a direction (Ex .: vertical, horizontal) and a direction (Ex .: forward, upwards). However, for elementary problems, where there is displacement in only one direction, the so-called one-dimensional movement, it is advisable to treat it as a scalar quantity (with only numerical value).
The mass of an object is not an important factor in determining the speed of that object. However, time, direction and distance are important factors in determining speed.
Answer:
Passivation of Oxide layers of the metals.
Explanation:
Passivation is a non-electrolytic finishing process that makes most metals rust-resistant. The prosses removes free iron from the surface by using either nitric or citric acid. When this happens, it results to an inert, protective oxide layer that is very slow or less likely to chemically react with air and cause corrosion.
Passivity caused many of the metals several minutes to begin to react. Once the finishing process that makes metals less likely to react was eroded, reaction was initiated vigorously.