While the number nuclear protons as given is 34, and therefore we deal with the element selenium, there are 2 more electrons than protons, and therefore this species has an overall
2
−
charge.
We represent this selenide ion as
S
e
2
−
. Do I win 5 pounds?
Z= 34, therefore the atom is selenium
Answer:
N₂ = 6.022 × 10²³ molecules
H₂ = 18.066 × 10²³ molecules
NH₃ = 12.044 × 10²³ molecules
Explanation:
Chemical equation;
N₂ + 3H₂ → 2NH₃
It can be seen that there are one mole of nitrogen three mole of hydrogen and two moles of ammonia are present in this equation. The number of molecules of reactant and product would be calculated by using Avogadro number.
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
Number of molecules of nitrogen gas:
1 mol = 6.022 × 10²³ molecules
Number of molecules of hydrogen:
3 mol × 6.022 × 10²³ molecules/ 1 mol
18.066 × 10²³ molecules
Number of molecules of ammonia:
2 mol × 6.022 × 10²³ molecules/ 1 mol
12.044 × 10²³ molecules
Ionic bonds usually occur between metal and nonmetal ions. For example, sodium (Na), a metal, and chloride (Cl), a nonmetal, form an ionic bond to make NaCl. In a covalent bond, the atoms bond by sharing electrons. Covalent bonds usually occur between nonmetals.
Answer:
Option B. Malleable, Conductor, High melting point, Lustrous
Explanation:
Mg has a higher melting point because of the strong electrostatic force of attraction between the magnesium ions (Mg^2+). The rest properties listed are all general properties of metals
Answer: The total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
Explanation:
Given: Mass = 46 g
Initial temperature = 
Final temperature = 
Specific heat capacity of ice = 2.05 
Formula used to calculate the energy is as follows.
where,
q = heat energy
m = mass
C = specific heat capacity
= initial temperature
= final temperature
Substitute the values into above formula as follows.
Thus, we can conclude that the total energy, in kilojoules, that is needed to turn a 46 g block of ice at -25 degrees C into water vapor at 100 degrees C is 11.787 kJ.
