What causes the lines in the spectrum for elements

The electron configurations of two different atoms are shown below. each yellow electron has a charge of 1−, and the net charge of each nucleus is shown. these atoms will combine with bond. a. an ionic b. a positive c. a negative d. a covalent plzzz mee with !

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

Which set of characteristics best describes igneous rock? a) largest type of rock, made of organic matter, hardest type of rock b) least abundant type of rock, made of other rocks, made mostly of minerals c) found on all continents, contains wavy bands of stripes, contains fossils d) most abundant type in earth's crust, made of magma/lava, contains no fossils