<span> They </span>do<span> not </span>respond to stimuli<span>, they </span>do<span> not grow, they </span>do<span> not </span>do<span> any of the things we normally associate with life.
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Answer is: <span>concentration of fluoride in the water in parts-per-million is 1 ppm.
</span>Parts-per-million (10⁻⁶) is<span> present at one-millionth of a </span>gram per gram of sample solution, f<span>or example mg/kg.
</span>m(fluoride) = 500 g · 1000 mg/g = 500000 mg.
m(water) = d(water) · V(water).
m(water) = 1 kg/L · 500000 L.
m(water) = 500000 kg.
arts-per-million = 500000 mg ÷ 500000 kg = 1 mg/kg = 1 ppm.
Helium,it has an atomic mass of 4,which means total no. of protons and neutrons,so I think you meant 2 protons and an atomic mass of 4
Answer:
Enthalpy of formation = -947.68KJ/mol
Explanation:
Enthalpy of formation is the heat change when one mole of a substance is formed from its element in its standard states and in standard conditions of temperature and pressure. it may be positive or negative, if positive, it is an endothermic reaction where the heat content of the product is greater than that of the reactants, and if negative, it is exothermic reaction - where the heat content of the reactants is greater than the products. the enthalpy of formation is measured in KiloJoule/Moles (KJ/Mole).
From the value of the enthalpy of formation of NaHCO3, it shows that the reaction is exothermic, that is the formation of NaHCO3 from its constituents elements. As such, the heat content of the reactants is greater than the products.
The step by step explanation is shown in the attachment.
Ions are electrically charged particles formed when atoms lose or gain electrons. They have the same electronic structures as noble gases. Metal atoms form positive ions, while non-metal atoms form negative ions. The strong electrostatic forces of attraction between oppositely charged ions are called ionic bonds.