Answer:
Explanation By looking at past concentrations of greenhouse gasses in layers in ice cores, scientists can calculate how modern amounts of carbon dioxide and methane compare to those of the past, and, essentially, compare past concentrations of greenhouse gasses to temperature. Ice coring has been around since the 1950s.n:
Answer:
C. to explore the composition of Mars
Explanation:
Initially, in 2019, an unmanned mission is planned to orbit the moon. The spacecraft would flyby the moon. In 2020's, the Exploration Mission 2 would be a manned mission on the same path around the moon. This would be the base for future goal of collecting samples from mars. In later of 2020's unmanned spacecraft would be sent to mars and a robot would collect the samples from the Martian surface. In 2030's, a crew would be sent to Mars.
Answer:
Increasing atomic number - True
Explanation:
The modern table is based on Mendeleev’s table, except the modern table arranges the elements by increasing atomic number instead of atomic mass.
The Atomic number is the number of protons in an atom, and this number is unique for each element. For example, Hydrogen has an atomic number of 1, Calcium has an atomic number of 20.
In the modern periodic table the elements are further arranged into:
- rows, called periods, in order of increasing atomic number. Elements in the same periods have the same number of shells.
- vertical columns, called groups, where the elements have similar properties. Elements in the same group has the same number of valency (outermost number of electrons)
Answer:
A. observing
Explanation:
There are various steps that are involved in a scientific investigation. Observation is the first step of the scientific investigation. In this step, a close examination is laid on the investigation. Observation is collected with the senses and the information is gathered.
In the given excerpt, Clive missed the observation part of the scientific investigation. All the other three steps were followed by Clive. He was not able to observe the situation and so was not able to provide the answers to the questions asked by his classmates.