Answer:
SF4 -Covalent bond
BaBr2 - Ionic bond
Ca - Metallic bond
Explanation:
Sulphur and fluorine are non metals. Nonmetal atoms combine by the sharing of electrons. This is also called a covalent combination(bond).
In BaBr2, a metal is combined with a nonmetal. This combination involves a transfer of electrons from the metal to the nonmetal forming an ion pair. This is otherwise called an ionic bond.
Atoms of a metal are held together by strong metallic bonds that involves positively charged cations and a cloud of electrons.
C should be the answer to the following formula
Answer: 5.5
Explanation: Strontium titanate is both much denser (specific gravity 4.88 for natural, 5.13 for synthetic) and much softer (Mohs hardness 5.5 for synthetic, 6–6.5 for natural) than diamond.
Answer:

for the balanced equation

Answer:
At birth, there are approximately 1 million eggs; and by the time of puberty, only about 300,000 remain. Of these, only 300 to 400 will be ovulated during a woman's reproductive lifetime. Fertility can drop as a woman ages due to decreasing number and quality of the remaining eggs.
Explanation:
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