I need some help with my science homework. Well it is not really my homework it is my study guide but the actual test is the same as the study guide almost. They just switch around the words and stuff around to mess with your mind. These were just the only 7 problems I need help with out of all 100 problems in the study guide.
3.
The rows in the periodic table indicate the number of _______________ or energy levels
A) points
B) nucleus
C) particles
D) electron orbitals
4.
Columns indicate the number of _________________ in the outer shell.
A) quarks
B) neutrons
C) protons
D) electrons
25.
Calculate the number of moles in 34 grams of copper (Cu).
A) 0.54 moles Cu
B) 63.5 moles Cu
C) 34 moles Cu
D) 54 moles Cu
26.
Convert 22 grams of copper to atoms of copper (Cu). Hint: Remember Avogadro
A) 2.09 X 1023
B) 3.5 X 1023
C) 1.09 X 1023
D) 6.5 X 1023
27.
Calculate the number of g that are in 39.0 mol of CaO.
A) 2190 g or 2.19 x 103 g
B) 56g
C) 16 g or 1.6 x 103 g
D) 5190 g or 5.19 x 103 g
28.
Calculate the number of mol that are in 0.608 g of SiO2.
A) 0.0535 mol or 5.35 x 10-2 mol
B) 60.804 mol
C) 0.0608 mol or 6.08 x 10-2 mol
D) 0.0101 mol or 1.01 x 10-2 mol
25. A
34g Cu * 1 mole Cu/
63.54 which equals
.54
26. A
Sure, I can help you with these questions. Let's go through them one by one and explain how to find the answers.
3. The rows in the periodic table indicate the number of _______________ or energy levels.
To find the answer, you need to know the term used to describe the different energy levels in the periodic table. Each row, also known as a period, represents one energy level. So, the correct answer is D) electron orbitals.
4. Columns indicate the number of _________________ in the outer shell.
To determine the term for the number of particles present in the outer shell, you should recall the concept of valence electrons. The columns on the periodic table are called groups or families, and they indicate the number of valence electrons present in an element's outer shell. Therefore, the correct answer is D) electrons.
25. Calculate the number of moles in 34 grams of copper (Cu).
To solve this problem, you need to use the molar mass of copper (Cu). The molar mass of an element is the mass of one mole of that element. For copper, the molar mass is 63.5 g/mol. Using this information, you can calculate the number of moles by dividing the given mass (34 g) by the molar mass (63.5 g/mol). The resulting value is approximately 0.54, so the correct answer is A) 0.54 moles Cu.
26. Convert 22 grams of copper to atoms of copper (Cu). Hint: Remember Avogadro.
To convert grams of copper to atoms of copper, you need to use Avogadro's number (6.022 x 10^23 atoms/mol). First, calculate the number of moles of copper by dividing the given mass (22 g) by the molar mass of copper (63.5 g/mol). The result is approximately 0.347 moles. Then, multiply the number of moles by Avogadro's number to find the number of atoms. The correct answer is A) 2.09 x 10^23.
27. Calculate the number of g that are in 39.0 mol of CaO.
To solve this question, you need to use the molar mass of CaO. Calcium has a molar mass of approximately 40.1 g/mol, and oxygen has a molar mass of approximately 16.0 g/mol. Add these values to calculate the molar mass of CaO, which is 56.1 g/mol. Multiply the molar mass by the given number of moles (39.0) to find the mass in grams. The correct answer is A) 2190 g or 2.19 x 10^3 g.
28. Calculate the number of mol that are in 0.608 g of SiO2.
To find the number of moles, divide the given mass (0.608 g) by the molar mass of SiO2. Silicon has a molar mass of approximately 28.1 g/mol, and oxygen has a molar mass of approximately 16.0 g/mol. Multiply the molar mass of SiO2 by 2 (since it contains two oxygen atoms) and add the values to calculate the molar mass of SiO2, which is approximately 60.1 g/mol. Divide the given mass by the molar mass to find the answer. The correct answer is C) 0.0608 mol or 6.08 x 10^-2 mol.
I hope this helps you with your science study guide! If you have any additional questions, feel free to ask.