Answer:1, 2, and 4
Explanation:
covalent bonds are not ionic. the elements SHARE electrons
Which of the following are properties of compounds formed by covalent bonding (Select all that apply)
1. When you dissolve an covalent compound in water, the solution does not conduct electricity.
2. Covalent compounds often have lower melting points than ionic compounds.
3. When you dissolve an covalent compound in water, the solution conducts electricity.
4. Covalent compounds form when combining two or more nonmetal atoms.
5. Covalent compounds form when combining a two metal atoms.
6. Covalent compounds form when combining a metal atom with a nonmetal atom.
Answer: 10 ml of 200 mM 
is required and 30 ml of water is required.
Explanation:
According to the dilution law,
where,
= concentration of stock solution = 200mM
= volume of stock solution = ?
= concentration of resulting solution= 50mM
= volume of another acid solution= 40 ml
Thus 10 ml of 200 mM is required and (40-10) ml = 30 ml of water is to be added to make 40 ml of 50mM .
72 percent is hydrogen. Nuclear fusion converts hydrogen into other elements. The sun is also composed of about 26 percent helium and trace amounts of other elements; oxygen, carbon, neon, nitrogen, magnesium, iron and silicon.
http://www.space.com/17170-what-is-the-sun-made-of.html
All igneous rocks are defined by texture and gas content. Hope this helped, my man.
