I need help ! I don’t understand the concept of this question

Which statement best describes how atoms combine to form sodium chloride (nacl)? a. a positively charged sodium ion and a positively charged chlorine ion form an covalent bond. b. a positively charged sodium ion and a negatively charged chlorine ion form an covalent bond. c. a positively charged sodium ion and a positively charged chlorine ion form an ionic bond. d. a positively charged sodium ion and a negatively charged chlorine ion form an ionic bond.

Base your answer on the information below and on your knowledge of chemistry. nitrogen dioxide, no2, is a dark brown gas that is used to make nitric acid and to bleach flour. nitrogen dioxide has a boiling point of 294 k at 101.3 kpa. in a rigid cylinder with a movable piston, nitrogen dioxide can be in equilibrium with colorless dinitrogen tetroxide, n2o4. this equilibrium is represented by the equation below. 2no2(g) n2o4(g) + 58kj at standard pressure, compare the strength of intermolecular forces in no2(g) to the strength of intermolecular forces in n2(g).

98 points you will be galileo perform the experiment to determine if objects with different mass fall at the same, or different, rates in the air and in a vacuum. before you conduct your experiment, you need to form a hypothesis. a hypothesis is a prediction of what you think will happen in the experiment. the hypothesis is a statement that describes “if” a certain set of circumstances are present “then” there will be a specific result that will occur. record your hypothesis here: record the results from step one of the experiment (dropping the objects in the air): first trial: second trial: third trial: record the results from step two of the experiment (dropping the objects in a vacuum): first trial: second trial: third trial: did the experiment support your hypothesis? using the data from your experiment, describe why you believe your hypothesis was either proven or disproven. what forces were acting on the objects dropped in the air? what force was acting on the objects dropped in the vacuum? part two: comparing forces choose two forces and compare and contrast these forces. you must provide two ways that they are alike and two ways that they are different. you may make a list, write in paragraph form, or make a chart. choose two forces and compare and contrast these forces. these must be different forces than used in the prior question. provide two ways that they are similar and two ways that they are different. you may make a list, write it out, or make a chart.