Answer:
15.75g
Explanation:
Rearrange the formula: density = mass/volume, so that mass is the subject: mass = density × volume
Now substitute (plug in) the known values into the formula:
mass = 10.5 × 1.5 ⇒ mass = 15.75g
The mass of the silver necklace is 15.75g
Hope this helps!
Answer:
that's because....
group 1 (e.g Na, K) those tend to lose one electron to gain noble gas electron configuration.
they can achieve that by just losing one electron from their outer shell.
as you go down the group 1, element gets bigger in size, which means there is more space between nucleus (which is in center of atom) and electron of outer shell. the more far away they are the less attraction force between them.
so its easier for potassuim to lose one electron than for lithuim.
so that means potassium will easily give up 1 electron to react with non metal or other element therefore it is more reactive than lithuim
but in case of non metal, the opposite happens but simple to understand.
as you go down the group 7 (halogen- Cl, Br, I) element will get bigger therefore force between nucleus and outer electron is getting smaller. they have to gain 1 electron in order to fill the outer shell (to gain noble gas electron configuration.)
as florine is more smaller in size than clorine it is more reactive because florine has more tendency to pull extra electron from metal or other element towards its side. so it easily gain 1 electron to react.
<span>Raising
the temperature of the reactants increases the reaction between the reactants.
The kinetic energy of the molecules of the reactants collides more frequently
with ach other thereby increasing its reaction. Increasing the concentration of
the reactants increases the reaction rate. Adding a catalyst to the reaction
increases the rate of reaction of a substance. The catalyst hastens the
chemical reaction. </span>
I believe it is b. you only want to change one thing at a time so you know which one thing caused the effect
