Answer:
66.7 g
Explanation:
Number of atoms = 2×10²¹
Mass of 2×10²¹ atoms = 0.4 g
Mass of 0.5 moles of that element = ?
Solution:
1 mole contain 6.022×10²³ atoms
2×10²¹ atoms × 1 mol / 6.022×10²³ atoms
0.33×10⁻² mol
0.003 mol
0.003 mole have mass of 0.4 g
0.5 mol have mass 0.5/0.003×0.4 g = 66.7 g
Answer:
Explanation:
Building Vocabulary
Match each term with its definition by writing the letter of the correct definition on
the line beside the term in the left column.
5. nucleus b
6. proton f
7. neutron h
8. electron d
9. atomic number g
10. isotopes c
11. mass number a
12. energy level e
a. the sum of protons and neutrons in the nucleus of an
atom
b. the very small center core of an atom
c. atoms of the same element that differ in the number
of neutrons, but have the same number of protons
d. the particle of an atom that moves rapidly in the
space outside the nucleus
e. a specific amount of energy related to the movement
of electrons in atoms
f. the particle of an atom with a positive charge
g. the number of protons in the nucleus of every atom
of an element
h. the particle of an atom that is neutral
-. mass number a.
12. energy level e
The answer to this problem is Beryllium is an alkaline earth metal.
