C) we can see Sirius as it looked 8.8 light years ago.
Answer:
Carson models how the continental crust varies in thickness. Marisol records atmospheric and oceanic temperatures at several beaches. Eliza analyzes seismic wave activity from an earthquake using a computer model.
Kr 4d10 5s2 5p2 would be your answer.
Avegadro's number = 6.02 x10^23 atoms
so
3.5g x 1mol/63.55g Cu x 6.02 x 10^23/ 1mol=3.32 x 10^22 atoms
Answer : The number of significant figures present in given number 230.0 are, 4
Explanation :
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
Rules for significant figures:
- Digits from 1 to 9 are always significant and have infinite number of significant figures.
- All non-zero numbers are always significant. For example: 654, 6.54 and 65.4 all have three significant figures.
- All zero’s between integers are always significant. For example: 5005, 5.005 and 50.05 all have four significant figures.
- All zero’s preceding the first integers are never significant. For example: 0.0078 has two significant figures.
- All zero’s after the decimal point are always significant. For example: 4.500, 45.00 and 450.0 all have four significant figures.
- All zeroes used solely for spacing the decimal point are not significant. For example : 8000 has one significant figure.
As we are given the number 230.0.
According to the rule, all zero’s after the decimal point are always significant. So, the number of significant figures present in given number 230.0 are, 4.
Hence, the number of significant figures present in given number 230.0 are, 4
