Answer:
option A is correct ( sodium, calcium and barium)
Explanation:
Given compounds:
Sodium chloride , calcium sulfide, barium oxide
We know that metals form positive ions. In order to solve the problem we must identify the metals from given compounds.
Na⁺Cl⁻
Ca²⁺S²⁻
Ba²⁺O²⁻
We can see that sodium, calcium and barium contain positive charges.
Thus option A is correct.
Because sodium have one valance electron. When it combine with chlorine sodium lose its one electron to complete the octet and chlorine accept it to complete its octet. Thus sodium form positive ion and chlorine form negative ion.
Similarly barium and calcium are present in group 2. Both have two valance electron. When they lose them cation are formed.
Other option are incorrect because,
Option B have sulfur and oxygen which are anion.
Option C have chlorine which is also anion
Option D have chlorine, sulfur and oxygen that are anions.
Answer:
The displacement reactions are regarded as redox reactions because they involve the formal transfer of electrons from one chemical specie to the other
2) The series of reactivity of the metals in the order of increasing reactivity are;
↓
↓
Explanation:
1) Redox (oxidation-reduction) reaction is a chemical reaction involving the loss and gain of electrons from one chemical species to another, where the chemical species that undergoes oxidation, loses electrons and is termed the reducing agent, while the other chemical species that undergoes reduction, gains electrons, and is termed the oxidizing agent
2) The redox reaction can being based on the affinity for electrons depends on the positions of the reactants in the electrochemical series as well as the chemical reactivity of the metals with zinc being a stronger reducing agent and more chemically reactive than copper and magnesium being a stronger reducing agent and more chemically reactive than zinc
Least reactive (Cu) < (Zn) < Mg Most reactive
Copper < Zinc < Magnesium.
Answer: Option (b) is the correct answer.
Explanation:
When there are more number of hydroxide ions in a solution then there will be high concentration of 
or hydroxide ions. As a result, more will be the strength of base in that particular solution.
A base is strong when it readily dissociate into its ions in the solution. When a base is strong, then it does not matter at what concentration it is dissolved in the solution because despite of its low concentration it will remain a strong base.
Thus, we can conclude that out of the given options, the statement even at low concentrations, a strong base is strong best relates the strength and concentration of a base.
I would say B because c and d would decrease competition and a would do the same, or just kill the ecosystem.
Hope this helps and don't forget to hit that heart :)
Answer: 72.93 litres
Explanation:
Given that:
Volume of gas (V) = ?
Temperature (T) = 24.0°C
Convert 24.0°C to Kelvin by adding 273
(24.0°C + 273 = 297K)
Pressure (P) = 1.003 atm
Number of moles (n) = 3 moles
Molar gas constant (R) is a constant with a value of 0.0821 atm L K-1 mol-1
Then, apply ideal gas equation
pV = nRT
1.003 atm x V = 3.00 moles x 0.0821 atm L K-1 mol-1 x 297K
1.003 atm•V = 73.15 atm•L
Divide both sides by 1.003 atm
1.003 atm•V/1.003 atm = 73.15 atm•L/1.003 atm
V = 72.93 L
Thus, the volume of the gas is 72.93 litres
