Answer:
D. Halogens
Explanation:
All elements in these groups have 7 valence electrons, meaning their electronegativity is the highest among the elements.
Answer and explanation:
A) An ideal fuel must:
- easy to transport and storage.
- have a high calorific value.
B) The <em>calorific value</em> for a fuel is the amount of heat - measured in Joules- which is produced during the complete combustion of the fuel. It is expressed in Joules per Kg of fuel (J/kg).
C) From the data:
mass of fuel = 2 kg
heat produced = 48,000 KJ
We calculate the calorific value by dividing the heat produced by the mass of fuel, as follows:
calorific value = heat produced/mass of fuel = (48,000 KJ)/(2 kg)= 24,000 kJ/kg
Since 1 KJ= 1000 J, we can express the calorific value in J/kg as follows:
24,000 kJ/kg x 1000 J/1 kJ = 2.4 x 10⁷ J/kg
Answer: Mixture
Explanation:
Element is a pure substance which is composed of atoms of similar elements.
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. Example: Air which conatins a mixture of 
, 
, 
and 
The reaction Pb(NO3)2(aq) + NiCl2(aq)---------> PbCl2(s) + Ni(NO3)2(aq) is a precipitation reaction.
A chemical reaction is said to occur when two or more substances are combined to produce new substances. Chemical reactions are classified based on the kind of change taking place in the reaction.
In the reaction;
Pb(NO3)2(aq) + NiCl2(aq)---------> PbCl2(s) + Ni(NO3)2(aq)
We can see that a solid is formed when lead II nitrate reacts with nickel II chloride. This is a precipitation reaction.
Learn more: brainly.com/question/5624100
A. Acids increase the number of OH- ions in a solution. FALSE
B. Bases increase the number of OH- ions in a solution. TRUE
C. Acids increase the number of H+ ions in a solution. TRUE
D. Bases increase the number of H+ ions in a solution. FALSE
