6th Grade Science – Week 13
1. The nucleus of most atoms is composed of
(A) tightly packed protons.
(B) tightly packed protons and neutrons.
(C) tightly packed neutrons.
(D) loosely connected protons and electrons.
2. Isotopes are atoms of the same element that have different
(A) principal chemical properties.
(B) number of protons.
(C) number of neutrons.
(D) number of electrons.
3. Carbon-14, the radioactive nuclide used in dating fossils, has
(A) 10 neutrons.
(B) 6 neutrons.
(C) 14 neutrons.
(D) 8 neutrons.
4. How many protons, neutrons, and electrons does Chlorine-35 have?
(A) 17 protons, 35 neutrons, 17 electrons
(B) 17 protons, 18 neutrons, 18 electrons
(C) 17 protons, 18 neutrons, 17 electrons
(D) 17 protons, 35 neutrons, 35 electrons
5. What substance will have 29 protons, 34 neutrons, and 28 electrons.
(A) 63Zn+2
(B) 63Cu+2
(C) 63Zn+
(D) 63Cu+
6. How many protons and electrons does O2- have?
(A) 8 protons, 6 electrons
(B) 8 protons, 10 electrons
(C) 8 protons, 9 electrons
(D) 8 protons, 8 electrons
7. An aluminum atom consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is
(A) 27
(B) 40
(C) 13
(D) 26
6th Grade Science – Week 13
8. Which of the following statements is/are true about the atom shown above?
I) this atom has 25 protons
II) this atom has 25 neutrons
III) this atom has 21 electrons
(A) I and II only
(B) I and III only
(C) II and III only
(D) I, II, and III
9. The atomic number of a certain element is 19, and its atomic weight is 39. An atom of the element
contains __________ protons, __________ neutrons, and the chemical symbol for the element is
__________.
(A) 19, 19, Fluorine
(B) 19, 20, Fluorine
(C) 20, 19, Potassium
(D) 19, 20, Potassium
10. What substance has 35 protons, 45 neutrons, and 36 electrons?
(A) 81Br –
(B) 80Br –
(C) 80Br –2
(D) 81Br –2