A. True
if cold air is replacing warm air it is a cold front and vice versa.
<span>It can form four covalent bonds. </span>
Answer:
a) Yes, there are
shakes in a second (
) in a year there are 31,536,000 seconds... that is 3.1536x
(
)
b) Note that the defined universe day will have 60*60*24=86400 universe seconds if the seconds are defined as normal seconds.
Also one universe day (or 86400 universe seconds) is equivalent to 1010 years. Now using a rule of three we can know the seconds that humans have existed.

That is about 2 and half hours.
Answer:

Explanation:
When an amount of energy Q is supplied to a substance of mass m, the temperature of the substance increases by
, according to the equation

where
is the specific heat capacity of the substance.
In this problem, we have:
is the amount of heat supplied to the sample of gold
m = 0.1 kg = 100 g is the mass of the sample
is the specific heat capacity of gold
Solving for
, we find the change in temperature

And since the final temperature was

The initial temperature was
