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sergejj [24]
3 years ago
15

Can you please answer number 8 thanks

Chemistry
1 answer:
MAXImum [283]3 years ago
4 0
A day is added to February every four tears as a corrective measure. The Earth does not exactly revolve around the sun for 365 days. There is a small offset that is corrected by adding a day to February. This happens every four years and it is called Leap year.
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Red, green and blue light all have the same frequency and wavelength. True or false
Sedaia [141]
False, they are all different because they help you know different things.
4 0
3 years ago
Is the law of conservative mass observed in this equation CaCO3 + 2HCI -->CaCI2 +H2O + CO2
pychu [463]

Answer:

The law is observed in the given equation.

Explanation:

CaCO₃ + 2HCI → CaCI₂ +H₂O + CO₂

In order to find out if the law of conservative mass is followed, we need to <u>count how many atoms of each element are there in both sides of the equation</u>:

  • Ca ⇒ 1 on the left, 1 on the right.
  • C ⇒ 1 on the left, 1 on the right.
  • O ⇒ 3 on the left, 3 on the right.
  • H ⇒ 2 on the left, 2 on the right.
  • Cl ⇒ 2 on the left, 2 on the right.

As the numbers for all elements involved are the same, the law is observed in the given equation.

8 0
3 years ago
Lisa is using a spring scale to measure the weight of a wooden block. She weighs the wooden block a total of five times with the
Alchen [17]

Answer:

A)The spring scale has a high level of precision and a low level of accuracy.

Explanation:

Hope it works for u guys

3 0
4 years ago
If a neutral atom has 10 proton how many electrons would it have?
olchik [2.2K]
It should have 10 electrons
7 0
3 years ago
Read 2 more answers
A fossil was analyzed and determined to have a carbon-14 level that is 70 % that of living organisms. The half-life of C-14 is 5
Citrus2011 [14]

Answer: 2948

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

k=\frac{0.69}{t_{\frac{1}{2}}}=\frac{0.693}{5730}=1.21\times 10^{-4}years^{-1}

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  = 1.21\times 10^{-4}years^{-1}

t = age of sample  = ?

a = let initial amount of the reactant  = 100

a - x = amount left after decay process = \frac{70}{100}\times 100=70

t=\frac{2.303}{1.21\times 10^{-4}}\log\frac{100}{70}

t=2948years

Thus the fossil is 2948 years old.

5 0
3 years ago
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