hey, i have a few questions with chemistry. answers only or all if you'd like.
1. Which of the following can best distinguish a physical change from a chemical change?
a. energy is absorbed or released b. a color change occurs
c. a gas is produced d. mass is converted
2. The nucleus of an atom is:
a. negateively charged and has a low density
b. negatively charged and has a high density
c. positively charged and has a low density
d. positevely charged and has a high density
3. The number of neutrons in the nucleus of an atom can be calculated by:
a. adding together the numbers of electrons and protons
b. subtracting the number of protons from the number of electrons
c. subtracting the number of prtons from the mass number
d. adding the mass number to the number of protons
4. The sum of the protons and neutrons in an atom equals the:
a. atomic # b. atomic mass
c. # of electrons d. mass #
5. All atoms of the same element have the same:
a. number of protons
b. number of neutrons
c. mass number
d. mass
6. The identity of an element can be determined on the basis of which of the following:
a. the number of protons in an atom of the element
b. the number of neutrons in an atom of the element
c. the mass number of the element
d. the atomic mass of the element
7. What is the ionic charge on the chromium ion in the ionic compound that has the formula: Cr2O3
a. +3
b. -2
c. -5
d +5
1. Which of the following can best distinguish a physical change from a chemical change?
a. energy is absorbed or released b. a color change occurs
c. a gas is produced d. mass is converted
2. The nucleus of an atom is:
a. negateively charged and has a low density
b. negatively charged and has a high density
c. positively charged and has a low density
d. positevely charged and has a high density
3. The number of neutrons in the nucleus of an atom can be calculated by:
a. adding together the numbers of electrons and protons
b. subtracting the number of protons from the number of electrons
c. subtracting the number of prtons from the mass number
d. adding the mass number to the number of protons
4. The sum of the protons and neutrons in an atom equals the:
a. atomic # b. atomic mass
c. # of electrons d. mass #
5. All atoms of the same element have the same:
a. number of protons
b. number of neutrons
c. mass number
d. mass
6. The identity of an element can be determined on the basis of which of the following:
a. the number of protons in an atom of the element
b. the number of neutrons in an atom of the element
c. the mass number of the element
d. the atomic mass of the element
7. What is the ionic charge on the chromium ion in the ionic compound that has the formula: Cr2O3
a. +3
b. -2
c. -5
d +5