Answer:
phosphorus - least similar to barium
beryllium - most similar to barium
Explanation:
The formula of the chloride formed between barium and chlorine is BaCl2.
Barium is a metallic element and has the valency of +2. Beryllium is also a group two metal with a valency of +2. Hence the compound formed between beryllium and chlorine is BeCl2
Phosphorus is a nonmetal and forms a completely different chloride from BaCl2. The chloride of phosphorus is PCl5 and PCl3. These are least similar to BaCl2
Answer:
0.50 moles of Cu
Explanation:
The balanced chemical equation for given synthetic reaction is,
2 Cu + S → Cu₂S
According to balance chemical equation,
1 mole of Cu₂S is produced by = 2 moles of Cu
So,
0.25 moles of Cu₂S will be produced by = X moles of Cu
Solving for X,
X = 0.25 mol × 2 mol / 1 mol
X = 0.50 moles of Cu
Hence, as the molar ratio of Cu to Cu₂S is 2:1 hence, to produce 0.25 moles of Cu₂S we will need 0.50 moles of Cu.
Answer:
.
Explanation:
Based on the electron configuration of this ion, count the number of electrons in this ion in total:
.
Each electron has a charge of 
.
Atoms are neutral and have 
charge. However, when an atom gains one extra electron, it becomes an ion with a charge of . Likewise, when that ion gains another electron, the charge on this ion would become 
.
The ion in this question has a charge of . In other words, this ion is formed after its corresponding atom gains two extra electrons. This ion has 
electrons in total. Therefore, the atom would have initially contained 
electrons. The atomic number of this atom would be 
.
Refer to a modern copy of the periodic table. The element with an atomic number of is sulphur with atomic symbol 
. To denote the ion, place the charge written backwards ("
" for a charge of ) as the superscript of the atomic symbol:
.
Answer:
C. The child must have inherited sickle cell genes from both parents.
Explanation:
Because of the fact that sickle cell disease is recessive, the child would have to get the gene from both parents.
