Login
Remember
Register
EasyElimu Questions and Answers
Questions
Unanswered
Tags
Users
Ask a Question
Ask a Question
Element A has mass number 40 and 21 neutrons
0
votes
720
views
asked
Jun 21, 2021
in
Chemistry Form 2
by
anony mous
Element A has mass number 40 and 21 neutrons
Write the electron arrangement of element A.
Give the formula of the compound formed when element A reacts with Sulphur. (S = 16.0)
structure of the atom
periodic table
electron arrangement
formula
Please
log in
or
register
to answer this question.
1
Answer
0
votes
answered
Jun 21, 2021
by
anony mous
No. of electrons; 40−21=19
Electron arrangement; 2.8.8.1 or
2 8 8 1 or 2,8,8,1, or 2:8:8:1
A
2
S or SA
2
or K
2
S or SK
2
Please
log in
or
register
to add a comment.
Related questions
0
votes
1
answer
An element has isotopic species A and B each with a mass number 39 and 40 respectively. The percentage of A is 60% and B is 40% for an isotopic element X. Calculate the relative atomics mass of X.
asked
Jul 7, 2021
in
Chemistry Form 2
by
anony mous
structure of the atom
isotopes
relative atomic mass
0
votes
1
answer
Study the table below and use it to answer the questions that follow. (The letters do not represent the actual symbols of the elements). Element S P Q R T Atomic Number 5 20 3 18 5 Atomic mass 10 40 7 40 11 Select two letters that represent a pair of isotopes
asked
Jul 5, 2021
in
Chemistry Form 2
by
anonymous
structure of the atom
0
votes
1
answer
The atomic number of element A is 11 and that of B is 8
asked
Jul 7, 2021
in
Chemistry Form 2
by
anony mous
structure of the atom
structure and bonding
0
votes
1
answer
An element, A, has 30 protons and 35 neutrons. What is
asked
Aug 5, 2021
in
Chemistry Form 2
by
anonymous
structure of the atom and the periodic table
0
votes
1
answer
write the electronic configuration of calcium (atomic number 20) and magnesium (atomic number 12)
asked
Aug 4, 2021
in
Chemistry Form 2
by
anony mous
structure of the atom and the periodic table
structure of the atom
Welcome to EasyElimu Questions and Answers, where you can ask questions and receive answers from other members of the community.
Categories
All categories
Mathematics
(632)
English
(287)
Kiswahili
(559)
Chemistry
(663)
Chemistry Form 1
(225)
Chemistry Form 2
(177)
Chemistry Form 3
(183)
Chemistry Form 4
(77)
Physics
(604)
Biology
(659)
Geography
(537)
History
(568)
CRE
(365)
IRE
(53)
Agriculture
(519)
Business Studies
(379)
Computer Studies
(20)
Home Science
(60)
General Questions
(432)
6.4k
questions
9.6k
answers
6
comments
590
users
...