Answer: The Lattice energy is the energy required to separate an ionic solid into its component gaseous ions <em>or</em>
It is the energy released when gaseous ions combine to form an ionic solid.
Explanation:
The lattice energy depends on the ionization energies and electron affinities of atoms involved in the formation of the compound. The ionization energies and electron affinities also depends on the ionic radius and charges of the ions involved. As the ionic radius for cations <em>increases</em> down the groups, ionization energy <em>decreases</em>, whereas, as ionic radii <em>decreases</em> across the periods , ionization energy <em>increases</em>. The trend observed for anions is that as ionic radii <em>increase </em>down the groups, electron affinity <em>decreases. </em>Across the period, as ionic radii <em>increases</em> electron affinity <em>increases</em>. Also, as the charge on the ion <em>increases,</em> it leads to an <em>increase</em> in energy requirement/content.
Therefore, for compounds formed from cations and anions in the same period, the highest charged cation and anion will have the highest lattice energy. For example, among the following compounds: Al2O3 (aluminium oxide), AlCl3 (aluminium chloride), MgO, MgCl2 (magnesium chloride), NaCl, Na2O (sodium oxide); Al2O3(aluminium oxide) will have the highest lattice energy, thus will be hardest to break apart because its ions have the highest charge.
It’s called an ion . An atom that loses electron is called an ion
Answer:
Volume of the sulfuric acid (25cm³), same mass of each metal (1g)
Explanation:
In an experiment, the CONTROL VARIABLE also known as constant is the variable that is kept unchanged for all groups in an experiment. This is done in order not to influence the outcome of the experiment.
In this case, students are trying to investigate the reactivity of four different metals. They added 1 g of each metal to 25cm³ of sulfuric acid and recorded the temperature change. Based on the explanation of control variable above, the VOLUME OF SULFURIC ACID (25cm³) and the MASS OF EACH METAL (1g) are the CONTROL VARIABLES because they are the same or unchanged in this experiment.
Answer:
option A = C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
Explanation:
Law of conservation of mass:
This law stated that mass can not be created or destroyed in chemical reaction. It just changed from one to another form.
For example:
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
28 g + 96 g = 88 g + 36 g
124 g = 124 g
This reaction correctly hold the law of conservation of mass.
Other options:
C + 4H₂ → CH₄
12 g + 8g = 16 g
20 g = 16 g
This reaction do not hold the law of conservation of mass.
3H₂O → 3H₂ + 3O₂
54 g = 6 g + 96 g
54 g = 102 g
This reaction do not hold the law of conservation of mass.
2Na + Cl → NaCl
46 g + 35.5 g = 58.5 g
81.5 g = 58.5 g
This reaction do not hold the law of conservation of mass.
Scientific investigation is the process in which scientist solve the problems by using different systematic approach. It can be initiated in different ways.
Experimental Scientific investigation: The investigation in which scientist answer the question on the basis of experimental results. Experimental investigation contains both dependent and independent variables, and only one variable is tested at a time is possible. This process makes uses of collecting observation and identifying the process in physical word.
Noting the colour of a solution when heated is the experimental scientific investigation
Therefore, other given options are part of scientific observation whereas Noting the colour of a solution when heated explains the experimental scientific investigation.
