There are two valence electrons in a single atom of magnesium.
Answer:
<h2>isotope is a variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.All isotopes of a given element have the same number of protons but different number of neutrons in each atom.</h2>
<h2>The 2 important physical properties of isotope is</h2>
<h2>1.<u>M</u><u>e</u><u>l</u><u>t</u><u>i</u><u>n</u><u>g</u><u> </u><u>Points</u></h2><h2>
2.<u>B</u><u>o</u><u>i</u><u>l</u><u>i</u><u>n</u><u>g</u><u> </u><u>Points</u></h2>
Answer:
I assume you mean as in elements
A metal "A metal is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typically malleable or ductile." (wiki)
a non-metal "In chemistry, a nonmetal is a chemical element that mostly lacks the characteristics of a metal. Physically, a nonmetal tends to have a relatively low melting point, boiling point, and density. A nonmetal is typically brittle when solid and usually has poor thermal conductivity and electrical conductivity." (wiki)
Explanation:
Answer:
A) secondary amide
Explanation:
When carboxylic acid reacts with a primary amine, a condensation reaction takes place with the elimination of a water molecule .
For example, ethanol reacts with methylamine which is a primary amine gives N-Methylacetamide and a water molecule as:

The bond formed which is
O
||
-- C ---NH ---
is known as secondary amide group as only one hydrogen is attached to nitrogen atom in the amide bond.
Answer:
13. c) Net
14. a) Gravity
15. d) Watt
16. b) the speed will suddenly decrease.
Explanation:
13. The <u>net </u> force is combination of all individual forces.
14. When we sit on the chair , then <u>gravitational force</u> acts on our body due to our mass.
F = mg
here, F = force due to gravity , g = acceleration due to gravity and m= mass of the body
15.Power : It is the force acting per unit area .It is discovered by James Watt

Its unit is
.In honor of the Scientist , its unit is Watt.
Watt = 
16. When the parachute first opens , the <u>speed of the skydiver suddenly decreases</u> because of the resistance offered by the air particles.(For more details look at the figure attached)
17. Transfer of momentum from one object to other is t<u>he law of conservation of momentum</u><u> </u>(NOT ENERGY).So the answer is<u> </u><u>False</u>
<u> Law of Conservation of Momentum : </u> Total momentum of a system is conserved if no external force attack on it. Momentum can neither be created nor destroyed but transferred from one form to other.