Answer:
5. An element's mass number tells the number of protons in its nucleus.
Atomic
6. Negatively charged particles in an atom are called electrons.
True
7. The cloud model of the atom describes the location of electrons as specific orbits around the nucleus.
Bohr
8. Atoms with the same number of protons but different numbers of neutrons are called isomers.
Isotopes
9. The sum of the protons and neutrons in an atom is called the atomic number.
Mass
10. An object that helps explain ideas about the natural world is called a model.
True
11. Mendeleev arranged his periodic table in order of increasing atomic number.
Mass
12. The rows in the periodic table are called periods.
True
13. Moving across the periodic table from left to right, one finds, in order, metals, then gases, then nonmetals.
Metalloids
14. Another name for a period is a family.
Group
15. On the periodic table, elements in the same column have similar properties.
True
Explanation:
32.7 g Zn
Explanation:
First convert the amount of gas into moles:
11.2 L H2 × (1 mol H2/22.4 L H2) = 0.500 mol H2
Then use the molar ratio to find the amount of zinc necessary to produce the amount of gas above:
0.500 mol H2 × (1 mol Zn/1 mol H2)
= 0.500 mol Zn
Now use the molar mass of zinc to find the number of grams of zinc for the reaction to occur:
0.500 mol Zn × (65.38 g Zn/1 mol Zn)
= 32.7 g Zn
Answer:
the pair of isotopes are b and e
the element with mass no of 19 is C
the element with atomic no 7is D
Explanation:
B and E are isotopes bcos they have the same atomic no, i.e no of protons. They bother have atomic no of 17 BUT have different mass no i.e sum of neutrons and protons.
(b)C is correct because the sum of the protons and neutrons is 19
(c) D because it has 7 protons
